Image Forming Apparatus

An image forming apparatus, comprising:

• a photosensitive drum;
• a developer cartridge comprising a developer roller and a protrusion that protrudes in an axial direction of the developer roller;
• a casing, to which the developer cartridge is attachable;
• a separator member configured to move the developer cartridge between a contact position, in which the developer roller contacts the photosensitive drum, and a separate position, in which the developer roller is separated from the photosensitive drum;
• and
• a first guide arranged to confront the protrusion of the developer cartridge along an orthogonal direction orthogonal to the axial direction in a state where the developer cartridge is attached to the casing, the first guide comprising a first guiding surface and a first inclined surface, the first guiding surface extending in parallel with a line that connects a center of a rotation axis of the developer roller with a center of a rotation axis of the photosensitive drum in a state where the developer roller is located in the contact position, the first inclined surface being located farther from the photosensitive drum than the first guiding surface and being continuous with the first guiding surface, the first inclined surface inclining with respect to the first guiding surface,
• wherein the protrusion of the developer cartridge contacts the first inclined surface when the separator member moves the developer cartridge toward the separate position.