As a boosting-type motor driving device using no reactor, a motor driving device capable of controlling boosting operation and motor driving at the same time is provided, and an automobile using the motor driving device is also provided. The motor driving device is used for driving a motor with a double-winding structure having a first set of three-phase windings and a second set of three-phase winding which are wound over a stator, and includes first and second inverters, which are connected respectively to the first set of three-phase windings and the second set of three-phase windings, thereby controlling the first and second inverters to control a driving force of the motor with the double-winding structure. The first and second inverters have positive and negative terminals which are connected respectively in common to a high-voltage battery. The motor driving device further includes a first switch unit connected between the positive terminals of the first and second inverters connected in common and a positive pole of the high-voltage battery, and a second switch unit connected between a neutral point of the second set of three-phase windings and the positive pole of the high-voltage battery.