An image forming apparatus is provided which does not mix sheets with non-qualified wireless tags into printed sheets, thereby increasing the printing speed. The image forming apparatus has a printingunit, a first reader/writer device, a second reader/writer device, and a control unit. The printing unit executes image forming movement for sheets. Before the execution of the image forming movement, the first reader/writer device executes read/write movement of any of data reading and writing on a wireless tag included in a sheet. The second reader/writer device executes the read/write movementafter the image forming movement is executed. The control unit controls the printing unit, the first reader/writer device and the second reader/writer device. The control unit at least executes non-qualification detection movement for detecting non-qualification of wireless tags in the second reader/writer device.