An image forming apparatus includes a shaft, a shaft support portion rotatably supporting the shaft, a shaft gear provided at an end portion of the shaft in a lengthwise direction, and a first gear engaged with the shaft gear and rotating the shaft gear. The rotation of the first gear applies a force acting toward the shaft support potion and the shaft contacts the shaft support portion by the force during rotation so that vibration of the shaft is restricted. An image forming apparatus includes a case having a door that can be opened and closed, a shaft provided in the case, a shaft support portion rotatably supporting the shaft, a shaft gear provided at an end portion of the shaft in a lengthwise direction, and a first gear engaged with the shaft gear and rotating the shaft gear. The first gear is engaged with the shaft gear when the door is closed and disengaged from the shaft gear when the door is open.