A motor control device controls driving of a motor, which outputs torque to a rack shaft as a load by rotation of a shaft fixed to a rotor. The motor control device has a rotation stress check unit for determining a rotation stress indicating a rotation stress, which is applied inversely from the load to a protection target member such as a shaft, bearing and oil seal related to the rotation of the shaft or torque transmission to the load. The rotation stress check unit determines the rotation stress is excessive based on that an absolute value of a rotation evaluation value exceeds a stress threshold value. The stress threshold value is set to be larger than an absolute value of an upper limit value realized in normal drive control.