In a DC power transmission and distribution line, a power cable line for making it possible to easily supply power to various electric power machines used for operation of the line is provided.A power cable line includes a power cable (1g, 1r, 1p, 1m, 1n) for executing DC transmission and distribution, an AC superposing section 2 for superposing an AC component on the power cable, and a branch power supply section 3 for taking out power induced by the superposed AC component from the cable. The AC component is superposed on the power cable by the AC superposing section 2 and AC power together with DC power is transmitted to the power cable. The superposed AC component is taken out by the branch power supply section 3 provided in a midway point of the cable and is supplied to various electric power machines.