An inkjet printing apparatus for printing images on printing paper by discharging ink while moving inkjet heads and the printing paper relative to each other. The apparatus includes an inkjet head holder for holding the inkjet heads, a controller for operating a plurality of motors to move the inkjet head holder vertically at least between a printing position and an origin position, and a monitoring unit for monitoring, during a vertical movement caused by the controller, synchronous rotations of the plurality of motors, and corresponding directions of rotation of the plurality of motors.