An image forming apparatus includes a sheet feeder attaching unit, a communication unit, a connection determining unit, an acquiring unit, a storage unit, a compatibility determining unit and a forcible unconnected control unit. The connection determining unit causes the communication unit to communicate with a communication section of a sheet feeder, and determines whether the sheet feeder is connected based on a communication result. The acquiring unit acquires attribute information of the sheet feeder. The storage unit stores attribute information of sheet feeders being compatible, in terms of control, with the image forming apparatus. The compatibility determining unit determines whether the connected sheet feeder is compatible by comparing the acquired attribute information of the connected sheet feeder with the stored attribute information. The forcible unconnected control unit establishes a forcible unconnected state between the connected sheet feeder and the image forming apparatus if the compatibility determining unit determines not-compatible.