To warm a floor surface efficiently while enhancing productivity and clamping a hot water pipe surely in stable state.

A substantially flat heat insulating soft cushion material layer 2 is formed on a hard substrate 1, a hot water pipe 3 is arranged on the surface of the soft cushion material layer 2, a hard surface plate 4 is pressure secured to the hard substrate 1 from the upper side of the hot water pipe 3, and the surface of the soft cushion material layer 2 is recessed by means of the hot water pipe 3, and the hot water pipe 3 is buried in this recess 5. The hot water pipe 3 is clamped by the hard surface plate 4 and the hard substrate 1.