A motor control device (4, 40) for driving a motor having an encoder configured to detect an operation of the motor, the motor control device (4, 40) comprising: a motor control unit configured to generate a command value to drive the motor so that the operation of the motor follows an operation command signal for driving the motor on the basis of the operation command signal and a feedback signal from the encoder corresponding to the operation of the motor; a drive unit configured to supply a drive current for driving the motor to the motor according to the command value from the motor control unit; an interruption unit configured to interrupt transfer of a drive signal accompanying the command value from the motor control unit to the drive unit; and a safety control unit configured to execute a process of interrupting the drive signal via the interruption unit when a determination is made that a failure has occurred in an operation of the encoder, wherein the safety control unit is configured to calculate an operation command value from the operation command signal, to determine occurrence of a failure in the encoder on the basis of a result of a comparison between a predetermined feedback value calculated from the feedback signal from the encoder and the operation command value, and to execute the process of interrupting the drive signal through the interruption unit on the basis of a result of the determination, characterized in that the encoder is configured to generate two independent feedback signals in response to the operation of the motor, and the safety control unit is configured to compare the two predetermined feedback values calculated from the two respective feedback signals with the operation command value to execute the process of interrupting the drive signal in the interruption process. a motor control unit configured to generate a command value to drive the motor so that the operation of the motor follows an operation command signal for driving the motor on the basis of the operation command signal and a feedback signal from the encoder corresponding to the operation of the motor; a drive unit configured to supply a drive current for driving the motor to the motor according to the command value from the motor control unit; an interruption unit configured to interrupt transfer of a drive signal accompanying the command value from the motor control unit to the drive unit; and a safety control unit configured to execute a process of interrupting the drive signal via the interruption unit when a determination is made that a failure has occurred in an operation of the encoder, wherein the safety control unit is configured to calculate an operation command value from the operation command signal, to determine occurrence of a failure in the encoder on the basis of a result of a comparison between a predetermined feedback value calculated from the feedback signal from the encoder and the operation command value, and to execute the process of interrupting the drive signal through the interruption unit on the basis of a result of the determination, characterized in that the encoder is configured to generate two independent feedback signals in response to the operation of the motor, and the safety control unit is configured to compare the two predetermined feedback values calculated from the two respective feedback signals with the operation command value to execute the process of interrupting the drive signal in the interruption process.