An image forming apparatus includes a drive unit, an image bearing member, a developing unit, a support unit, an urging member, and a switching mechanism. The urging member generates an urging force for pivoting the support unit in an approaching direction in which a peripheral surface of a developing roller is moved toward a peripheral surface of the image bearing member. The switching mechanism switches the support unit between a first position (fitting position) and a second position (releasing position). The support unit includes: a second drive input section disposed coaxially with a pivot shaft and for receiving a rotational drive force from a drive output shaft of the drive unit; and a transmission mechanism for transmitting the rotational drive force to a first drive input section. The rotation direction of the rotational drive force is for rotation in a direction of pivoting the support unit in the approaching direction.