To provide a cable protection circuit which is possible of reduction of cable cost and cable weight by minimizing the tolerable current value of a cable used for a motor driving circuit as much as possible.

A motor driving circuit, in which a power source 12 and a motor 14 are connected with each other by a cable 18, is provided with a circuit breaking means 16, and the circuit breaking means 16 is equipped with a return type circuit breaker 161, which can return to the previous state even if it operates once, and the minimum operation current Ib of the return type circuit breaker is set to be larger than the rated current value Ir of the motor 14, and the time taken for the return type circuit breaker 26 to operate in case that a current larger than the minimum operating current value Ib flows to the motor driving circuit is set to be shorter than the time taken for the cable 18 to burn, and the tolerable current value Ic of the cable 18 is set to be smaller than a motor lock current value If which flows to the motor driving circuit in case that the motor 14 is locked.