A motor control device includes a position sensor that detects a position of a motor, an AD converter that converts an analog signal, which is a detection value of a motor current, into a digital signal, and a control circuit that drives an inverter using an output signal of the AD converter. The control circuit starts the AD converter during a permission period, and performs processing for the analog-digital converter during an electrical half cycle including a permission period. The length of a prohibition period obtained by excluding a permission period from an electrical half cycle decreases as the rotating speed of the motor increases.