An image forming apparatus having a color mode and a monochromatic mode, which includes: a transmission member, which can be switched between a transmitted state where a motor transfers a drive force to a single photoreceptor drum and a non-transmitted state where the motor does not transfer the drive force to the single photoreceptor drum; and a controller which switches to the non-transmitted state while executing an image formation in the monochromatic mode, and when a command to execute a next image formation is not instructed, switches to the transmitted state after a phase adjustment of each photoreceptor drum after the image formation in the monochromatic mode, and controls the motor to execute a slight rotation operation at every prescribed period of time by synchronizing plural drums including the single photoreceptor drum with each other through the transmission member.