To simplify a structure and connecting work of the connecting part between a floor heating panel and warm water pipings embedded in floor concrete of warm water in warm water floor heating.

Flexible warm water piping 1, 2 coming through the inside of a sleeve embedded in floor concrete 4 are derived on the concrete surface by obliquely penetrating through a concrete floor to be smoothly raised up on the concrete surface to connect the pipe end to warm water inlet/outlet 7a, 7b of a floor heating panel 7 so as to cover a part appearing on the concrete floor upper surface of the warm water piping with a plastic cover panel 8a having the same thickness as the floor heating panel. This panel is formed into plural kinds such as a Y shape of passing warm water piping, a 1/4 circular arc shape or a shape of arranging a straight line-shaped groove 81 on the under surface.