An endless belt includes a base material layer, the base material layer containing a polymer material and conductive particles, wherein in a section of the base material layer in a thickness direction, the conductive particles have an area ratio of 9.0% or more and 14.5% or less, an average value of areas of Delaunay triangles taking centers of gravity of the conductive particles as vertices is 0.10 m.sup.2 or more and 0.90 m.sup.2 or less, and a standard deviation of the areas is 0.010 m.sup.2 or more and 0.080 m.sup.2 or less.

Provided is a sheet feeding device including: a cassette housing section; a sheet storage cassette; and a sheet feeding unit. The sheet storage cassette includes a cassette base which is configured to store recording media that have a sheet form, and can be inserted into and removed from the cassette housing section. The sheet feeding unit is provided in the cassette housing section, and is configured to feed the recording media to be stored in the sheet storage cassette. A pair of fixed-side rails that are made of metal and are attached to the cassette housing section. The cassette base is made of a resin. A pair of inner rails that are coupled to the pair of fixed-side rails so that the pair of inner rails are slidable are formed integrally with side surfaces of the cassette base.