An image forming apparatus, comprising: an image bearing member for bearing a toner image on a circumferential surface; a developing device including a developing roller for supplying toner to the circumferential surface of the image bearing member; a toner container to be assembled with the developing device to supply the toner to the developing device; a sheet conveyance path for conveying a sheet; a housing for accommodating the image bearing member, the developing device and the toner container, and having a first surface and a second surface to face to the first surface; a first cover which is provided on the first surface; and a second cover (12,25) which is provided on the second surface; wherein: the first surface is a surface through which the toner container is taken out from the interior of the housing to the outside of the housing; the second surface is a surface through which the developing device is taken out from the interior of the housing to the outside of the housing; the housing has a front surface to which a user will face, a rear surface opposite to the front surface, side surfaces, an upper surface and a bottom surface, the first surface is arranged on the front surface; and the second surface is arranged on the rear surface; the first cover is a cover for exposing a part of the toner container and allowing the toner container to be taken out from the interior of the housing to the outside of the housing by being opened with respect to the housing; and the second cover (12,25) is a cover for exposing a developer housing of the developing device and allowing the developing device to be taken out from the interior of the housing to the outside of the housing by being opened with respect to the housing, characterized in that; the toner container includes a container main body as a main toner storage location, a cylindrical portion projecting from the container main body, a toner discharge opening provided on the cylindrical portion, a rotating member for conveying the toner stored in the container main body to the toner discharge opening, and a container gear for inputting a rotational drive force to the rotating member, the container gear being arranged on the leading end surface of the cylindrical portion, the developing device includes the developer housing shaped to be long in a first direction along an axial direction of the developing roller, a toner supply opening perforated with the developer housing and used to receive the toner supplied from the toner container, and an input gear engaged with the container gear and transmitting the rotational drive force to the container gear, the toner container is assembled with the developing device in a direction along a second direction perpendicular to the first direction, and the container gear is engaged with the input gear when the developing device and the toner container are so assembled that the toner supply opening and the toner discharge opening of the toner container overlap in a vertical direction. an image bearing member for bearing a toner image on a circumferential surface; a developing device including a developing roller for supplying toner to the circumferential surface of the image bearing member; a toner container to be assembled with the developing device to supply the toner to the developing device; a sheet conveyance path for conveying a sheet; a housing for accommodating the image bearing member, the developing device and the toner container, and having a first surface and a second surface to face to the first surface; a first cover which is provided on the first surface; and a second cover (12,25) which is provided on the second surface; the first surface is a surface through which the toner container is taken out from the interior of the housing to the outside of the housing; the second surface is a surface through which the developing device is taken out from the interior of the housing to the outside of the housing; the housing has a front surface to which a user will face, a rear surface opposite to the front surface, side surfaces, an upper surface and a bottom surface, the first surface is arranged on the front surface; and the second surface is arranged on the rear surface; the first cover is a cover for exposing a part of the toner container and allowing the toner container to be taken out from the interior of the housing to the outside of the housing by being opened with respect to the housing; and the second cover (12,25) is a cover for exposing a developer housing of the developing device and allowing the developing device to be taken out from the interior of the housing to the outside of the housing by being opened with respect to the housing, characterized in that;