A powder container for storing powder inside includes a container main portion. The container main portion has a substantially cylindrical shape to rotate around a rotation axis of the container main portion to convey powder stored inside the container main portion in a conveyance direction along a direction of the rotation axis. The container main portion is a component made of paper formed by press working.

A developing device includes a cylindrical developing roller, a regulation member, a magnetic member, and a synthetic resin member. The regulation member includes a first opposing surface facing an outer circumferential surface of the developing roller. The magnetic member is arranged on a side surface of the regulation member. The synthetic resin member is arranged on a side surface of the magnetic member. The synthetic member includes a second opposing surface facing the outer circumferential surface of the developing roller. The second opposing surface is tilted at 40 or more but 60 or less with respect to the first opposing surface to be increasingly distant from the outer circumferential surface of the developing roller toward an upstream side in a rotating direction of the developing roller. A solubility parameter of a material of the synthetic resin member is 23 (J/cm.sup.3).sup.1/2 or more. Magnetic toner contains toner and resin fine particles.

A cartridge is configured to be attachable to a main body of an image forming apparatus and configured to receive toner supplied from a supply container. The cartridge includes a supply port configured to receive the toner supplied from the supply container, a shutter member configured to cover the supply port, and a locking member. The locking member is moved from a lock position to an unlock position to allow movement of the shutter member by using electric power supplied from the main body.

An image forming device is provided with a housing formed with an opening, a cover configured to move between a closing position and an opening position, and a plurality of process cartridges including a first process cartridge and a second process cartridge. The first and second process cartridges respectively include first and second photosensitive drums configured to rotate about first and second drum axes both extending in a first direction. The first and second developing devices are configured to supply toner to the first and second photosensitive drums, respectively. The first and second supplying devices are formed with first and second supply ports through which the toner to be supplied to the first and second developing devices are provided, respectively. Both the first and second supplying ports are opened to outside the housing.

A developing device includes a developing container, a developing roller, a regulating blade, a seal member, and a resin member. The regulating blade includes a mounting plate and a blade plate. The developing container has a facing part facing a step part due to thickness difference between the mounting plate and the blade plate. The seal member has a resin placement area, and is squeezed between the regulating blade and the facing part. The resin placement area is an area that penetrates the seal member and is surrounded by the seal member. The resin placement area overlaps the step part.

A cartridge is configured to be attachable to a main body of an image forming apparatus and configured to receive toner supplied from a supply container. The cartridge includes a supply port configured to receive the toner supplied from the supply container, a shutter member configured to cover the supply port, and a locking member. The locking member is moved from a lock position to an unlock position to allow movement of the shutter member by using electric power supplied from the main body.

A toner cartridge includes a first frame with a port to receive external air; a second frame forming a space together with the first frame; and a sheet-like filter to partition the space into an air chamber and a toner storage chamber, and to regulate toner flow while allowing air passage. The air chamber communicates with the port without the filter, and the toner storage chamber communicates with the port through the filter. The filter includes a first surface facing the air chamber, a second surface facing the toner storage chamber, and a third surface extending in the filter's thickness direction, and at least a part of the third surface is adhered to the first frame with an adhesive to be fixed.