To always feed safely and normally with a contactless method, without giving any unreasonable strain to a feeding cable, even for a large moving object having a large electric capacity requiring a large diameter, size and a heavy feeding cable.

At a storing position side A for a moving object 1, capable of making self-traveling along a constant horizontal passage between a storing position A and working position B, a cable accumulator 3 is attached and fixed, which is located at one end side in a longitudinal direction of a horizontal way, parallel to the horizontal passage and wind or take out a predetermined length of a feeding cable 9, one end portion of the feeding cable 9 taken out from the accumulator 3 is taken into a power-receiving section 1A of the moving object 1, a cable pulling traveling body 19, running in synchronization with the moving object 1, is provided, and a constant winding tension to the inside of the accumulator is given to the feeding cable 9 through a wire rope winch.