A motor control device comprising a plurality of control units corresponding to a plurality of windings (14, 15) which is provided in a motor, wherein: the motor control device is configured to control supply of electric power to the windings (14, 15) under the control of the plurality of control units based on various types of information acquired through communication between the plurality of control units; the plurality of control units includes a master control unit configured to generate a power supply control command value for controlling a motor torque generated by the motor as control information required for controlling supply of electric power to the windings (14, 15) and a slave control unit configured to control supply of electric power to the corresponding winding (14, 15) based on the newest power supply control command value by updating the power supply control command value generated by the master control unit when the power supply control command value is acquired through the communication between the control units; the plurality of control units includes at least one abnormality monitoring unit (53, 62, 64) configured to detect an abnormality in communication between the control units and to monitor a series of states until the abnormality is fixed when a predetermined condition is satisfied after the abnormality has been detected; characterised in that the slave control unit is configured to generate the power supply control command value based on information which is acquired through a path other than the communication between the control units and which is held in the slave control unit for use in control of supply of electric power to the windings (14, 15) in a normal state in which an abnormality in communication between the control units has not been detected, instead of the power supply control command value which is updated whenever the power supply control command value is acquired through the communication between the control units, and to perform backup control for holding the power supply control command value until the abnormality monitoring unit (53, 62, 64) fixes an abnormality in communication between the control units after detecting an abnormality in communication. the motor control device is configured to control supply of electric power to the windings (14, 15) under the control of the plurality of control units based on various types of information acquired through communication between the plurality of control units; the plurality of control units includes a master control unit configured to generate a power supply control command value for controlling a motor torque generated by the motor as control information required for controlling supply of electric power to the windings (14, 15) and a slave control unit configured to control supply of electric power to the corresponding winding (14, 15) based on the newest power supply control command value by updating the power supply control command value generated by the master control unit when the power supply control command value is acquired through the communication between the control units; the plurality of control units includes at least one abnormality monitoring unit (53, 62, 64) configured to detect an abnormality in communication between the control units and to monitor a series of states until the abnormality is fixed when a predetermined condition is satisfied after the abnormality has been detected; characterised in that the slave control unit is configured to generate the power supply control command value based on information which is acquired through a path other than the communication between the control units and which is held in the slave control unit for use in control of supply of electric power to the windings (14, 15) in a normal state in which an abnormality in communication between the control units has not been detected, instead of the power supply control command value which is updated whenever the power supply control command value is acquired through the communication between the control units, and to perform backup control for holding the power supply control command value until the abnormality monitoring unit (53, 62, 64) fixes an abnormality in communication between the control units after detecting an abnormality in communication.