To prevent a pipe from freezing to breakage by inserting an electric heating wire between a sheath pipe inside face and a pipe outside face and loading a voltage to the electric heating wire so as to generate heat from the electric heating wire.

A sheath pipe 4 is arranged on the earth floor or a concrete floor 10 below a floor plate 9, and a pipe 3 is inserted into the sheath pipe 4. A coated electric heating wire 5 is inserted with the pipe 3 into the sheath pipe 4, and one end of the coated electric heating wire 5 is connected to a terminal mounting part 61 in a voltage transducer 6. The coated electric heating wire 5 is heated to about 10-40°C when a voltage transduced to a low voltage by means of the voltage transducer 6 is loaded. Therefore, in winter, the coated electric heating wire 5 is heated when a current with a low voltage is let flow through the coated electric heating wire 5, so that the pipe 3 is prevented from being frozen and broken. Consequently, no equipment such as drainage from the pipe 3 is required. In addition, shock noise by a water hammer can be absorbed and reduced as the electric heating wire 5 is inserted between the sheath pipe 4 inside face and the pipe 5 outside face.