An image forming apparatus drives and rotates at least one of a photosensitive drum and a transport roller with use of a stepping motor in a multi-phase excitation mode. The image forming apparatus includes: a constant-voltage control unit controlling the stepping motor by applying a constant voltage for each phase; a constant-current control unit controlling the stepping motor by regulating an amount of current for each phase by a chopping control; a measuring unit measuring a chopping count of each phase on a per-step basis; a chopping count determination unit determining whether the chopping count of each phase is less than or equal to a predetermined count; and a control switching unit causing the constant-voltage control unit to control the stepping motor when the chopping count determination unit determines affirmatively, and causing the constant-current control unit to control the stepping motor when the chopping count determination unit determines negatively.