Motor control device

Provided is a motor control device having a function for determining a rotor position of a synchronous motor, without use of a sensor, the device prevents obtaining an erroneous rotor position, to enable stable control of the synchronous motor based on the rotor position in both the normal-control region and the flux-weakening-control region. The motor control device 1 includes: a first rotor position determining unit 19 that determines a rotor position of the synchronous motor 2 based on an induced voltage electrical angle, and a first induced voltage phase obtained from a current peak value and a difference between the induced voltage electrical angle and a current electrical angle; a second rotor position determining unit 20 that determines a rotor position of the synchronous motor 2 based on an induced voltage electrical angle, and a second induced voltage phase obtained from a flux linkage and a current peak value; and a selecting unit 21 that selects the first rotor position determining unit 19 or the second rotor position determining unit 20, based on a current peak value, and a first induced voltage phase or a second induced voltage phase.