To provide a motor driving apparatus capable of obtaining high detection resolution irrespective of whether a frequency of a signal from a detector is high or low. A motor driving apparatus (1) for driving a motor (3) includes an amplifier circuit (10) for receiving a signal from a detector (4) for outputting information including a position and a speed of the motor as the signal, and amplifying the received signal with a set amplification factor, a frequency detecting part (6) for detecting a frequency of the signal, and an amplification factor setting part (7) for changing setting of the amplification factor of the amplifier circuit (10) according to the frequency detected by the frequency detecting part.