An apparatus for moving a unit to execute scanning includes a scanning unit including a motor, an encoder for outputting a signal according to movement of the unit, a detection unit for detecting a current supplied to the motor, a speed control unit for executing a speed control of the motor according to the signal output from the encoder and the current detected by the detection unit, a movement control unit for setting a threshold value, moving the unit by driving the motor, by using the speed control unit, and a current control unit for setting a value greater than the predetermined value according to the threshold value and value of the current detected by the detection unit at a predetermined timing during a time period while the unit is moving.