Image carrier unit and image forming apparatus

An image carrier unit comprising:

• an image carrier;
• a unit casing configuring and positioned to rotatably support the image carrier;
• a protection cover, detachably mountable to the unit casing slidably in a rotational axis direction of the image carrier, configured to cover a part of the image carrier;
• an engage mechanism configured to engage the protection cover to the unit casing;
• the engage mechanism including:
• a first projecting portion, provided on a first end portion of the protection cover in a width direction perpendicular to the rotational axis direction of the image carrier, configured to project from the first end portion into one width direction;
• a first engaged portion, provided in the unit casing, configured to engage with the first projecting portion;
• a second projecting portion, provided on a second end portion of the protection cover in the width direction, configured to project from the second end portion into the one width direction;
• a second engaged portion, provided in the unit casing on a side opposite from the first engaged portion across image carrier in the width direction, configured to engage with the second projecting portion.