PURPOSE: To provide a wire insertion method, into an existing entry pipe passage, wherein a wire for pulling-into of a power cable is inserted into a pipe passage in which a subduct for pulling-into of an optical fiber has been laid and installed.

CONSTITUTION: A wire insertion method into an existing entry pipe passage is constituted in such a way that, in a pipe passage 1 which is provided with a subduct into which an optical fiber has been pulled, the inside of the pipe passage is filled with water, that a state that the subduct 3 is made to float at the upper part inside the pipe passage is kept, that a small pipe is then passed to a part at the lower part of the pipe passage 1 and that a wire for pulling-into of a power cable is passed.