To provide a heat storage floor for a floor heating device having reliability, superior durability, and a large heat capacity.

This heat storage floor 14 for the heat storage type floor heating device includes a plurality of heat storage vessels 102 planarly arranged under the floor and a heat feed pipe 13 feeding the heat thereto. The heat storage vessel 102 is provided with an approximately flat and rectangular parallelepiped body part, an upward mount part opened in a position at an approximately same height as that of the upper plate of the body part, and a lid airtightly closing the mount part, and the vessel inside is filled with water. A plurality of floor joists 114 are disposed on the upper surface of a permanent fulling board 112 covering the upper part of a heat insulating material 104 at prescribed intervals, three heat insulating boards 116 are disposed between the floor joists 114 on the upper surface of the permanent fulling board 112, and the heat storage vessel 102 is supported thereto. Floor boards 100 are laid on the floor joists 114. The heat feed pipe 13 is stored in a pipe storage groove 118 formed of the heat insulating plate 116. Aluminum sheets 124 are disposed between the heat insulating plate 116 and the heat storage vessel 102 and between the groove side surface 126 of the pipe storage groove 118 and the heat feed pipe 13.