A developer set includes a first developer and a second developer. The first developer contains a first toner containing first toner particles and a first carrier containing first carrier particles. The second developer contains a second toner containing second toner particles and a second carrier containing second carrier particles. The first toner particles and the second toner particles each include a toner mother particle and external additive particles attached to the surface of the toner mother particle. The external additive particles include spacer particles. The spacer particles have a number average primary particle diameter of at least 32 nm and no greater than 145 nm. The first carrier particles each include a first carrier mother particle and strontium titanate particles attached to the surface of the first carrier mother particle.

Toner particles in a developer include first strontium titanate particles attached to the surface of each toner mother particle thereof. The first strontium titanate particles have a content ratio of 0.3 to 0.9 parts by mass to 100.0 parts by mass of the toner mother particles. In the developer, coat layers of carrier mother particles of first carrier particles contain barium titanate particles and a coating resin including silicone resin. The barium titanate particles have a content ratio of 2 to 47 parts by mass to 100 parts by mass of the coating resin. Second strontium titanate particles attached to the surfaces of the carrier mother particles have a diameter of 15 to 85 nm.

A developing device includes a developing container storing a two-component developer containing a magnetic carrier and a toner, a developer carrying member carrying the developer on its outer circumferential surface, and a regulation member arranged to be opposed at a prescribed distance to the developer carrying member. The developer carrying member includes a developing sleeve on which a magnetic brush is formed, and a magnet secured in the developing sleeve and having a plurality of magnetic poles including a regulation pole opposed to the regulation member and a downstream-side magnetic pole arranged downstream of the regulation pole with respect to the rotation direction of the developing sleeve. The magnet is such that the vertical magnetic force gradient [mT/] has a local minimum value near a position at which the vertical magnetic force is 0 [mT] between the downstream-side surface of the regulation member and the downstream-side magnetic pole.

A carrier for electrostatic image development includes: resin-coated magnetic particles each including a magnetic particle and a resin layer that covers the magnetic particle; and strontium titanate particles composed of primary particles having an average circularity of 0.82 to 0.94 and an 84% cumulative circularity of more than 0.92.

Provided is a carrier for a developer of an electrostatic latent image, the carrier including a core particle, and a resin layer covering the core particle, where the resin layer includes metal compound particles, wherein the metal compound particles include magnesium compound particles or barium compound particles, and an exposed amount B (atomic %) of the magnesium or the barium on a surface of the carrier particle satisfies a relationship below:
10.0B 1.2.

An electrostatic charge image developer includes: a toner A incorporating toner particles and silica particles (A) as an external additive, the toner particles containing a binder resin and resin particles, and the silica particles (A) containing a nitrogen-containing compound containing the element molybdenum; and a carrier B incorporating a core and a coating resin layer, the coating resin layer covering the core and containing inorganic particles, and the ratio N.sub.Mo/N.sub.Si is 0.035 or greater and 0.45 or less, where N.sub.Mo and N.sub.Si are measured net intensities for the element molybdenum and the element silicon, respectively, in the silica particles (A) in x-ray fluorescence analysis.

An electrostatic image developer includes a toner including toner particles that include a binder resin and a release agent and have an exposure ratio of the release agent of 15% or more and 30% or less, and a carrier including magnetic particles and resin cover layers covering the magnetic particles and including inorganic particles, wherein the inorganic particles have an arithmetic average particle size of 5 nm or more and 90 nm or less, the resin cover layers have an average thickness of 0.6 ?m or more and 1.4 ?m or less, and a fine-irregularity-structure surface roughness of surfaces of the carrier three-dimensionally analyzed has, in an analysis region, a ratio B/A of an irregularity-surface area B to a plan-view area A of 1.020 or more and 1.100 or less.

A carrier is provided including a core particle and a resin layer coating the surface of the core particle. The resin layer includes fine metal particles, and a detected metal element amount A obtained by X-ray photoelectron spectrometry of the surface of the carrier is in a range of 4.0 atomic %A20.0 atomic % and an average major-axis length B of the fine metal particle exposing from the resin layer is in a range of 100 nmB800 nm.

Provided is a two-component developer for developing an electrostatic latent image incorporating: toner particles each containing a toner mother particle having an external additive on a surface of the toner mother particle; and carrier particles each having a core material particle and a covering layer containing a resin on a surface of the core material particle, wherein the external additive contains inorganic particles; the inorganic particles are subjected to surface modification with silicone oil; a carbon content remained on a surface of the inorganic particle after the surface modification is within 3.0 to 10.0 mass %; a free carbon ratio on the surface of the inorganic particle is 70.0% or more; the carrier particles have a resistance in the range of 1.010.sup.9 to 5.010.sup.10 .Math.cm; and the resin in the covering layer contains a resin formed from a monomer containing an alicyclic methacrylic acid ester monomer.

A carrier for electrostatic image development includes: resin-coated magnetic particles each including a magnetic particle and a resin layer that covers the magnetic particle; and strontium titanate particles composed of primary particles having an average circularity of 0.82 to 0.94 and an 84% cumulative circularity of more than 0.92.