Abstract: A disk drive apparatus comprises a movable member having a field part for driving a disk. A current path is formed from a DC power supply into one winding of a Q-phase winding of the movable member by a first FET power transistor of a first power amplifier and a second FET power transistor of a second power amplifier. The first power amplifier amplifies an input current into a conduction control terminal side using the first FET power transistor. The second power amplifier amplifies the input current into the conduction control terminal side using the second FET power transistor. A switching control part simultaneously controls Q conduction control terminal sides of the first power amplifying means in an on and an off state and causes the first FET power transistor of the first power amplifying means to perform an on and off high-frequency switching.