Image forming apparatus that facilitates positioning and attachment/detachment of image forming unit

An image forming apparatus comprising:

• an apparatus main body;
• an image forming unit attachable to and detachable from the apparatus main body along a predetermined attachment/detachment direction with respect to the apparatus main body;
• a guiding portion disposed in the apparatus main body, for guiding attachment/detachment of the image forming unit;
• a positioning mechanism disposed on the guiding portion, and provided with a first urging member and a unit-abutting portion for abutting on the image forming unit, the positioning mechanism positioning the image forming unit by urging the image forming unit when attached into the apparatus main body in a first position;
• and
• a posture-switchable lever member provided to be movable through a swing on the image forming unit, the posture-switchable lever member switching between a first posture in which the posture-switchable lever member locks the image forming unit in the first position within the apparatus main body, and a second posture in which the posture-switchable lever member releases the lock on the image forming unit and permits the image forming unit to be detached from the apparatus main body along the attachment/detachment direction.