To reduce radiation loss when a heating toilet stool is not used by forming a heat insulating material layer on the inner surface of a toilet stool lid, and forming a storing recessed groove for storing a heating surface of the heating toilet stool in a heating toilet stool contact part of the heat insulating material layer.

A heat insulating material layer 4 is formed on the inner surface of a toilet stool lid 2, and a storing recessed groove 6 for storing a heating surface 5 of a heating toilet stool 1 in which a heating unit is provided in the interior thereof is formed in the heat insulating material layer 4. The heat insulating material layer 4 is preferably formed by a soft synthetic resin foam body with a high foam rate, and a polyethylene foam body, for example, is used. As the heat insulating material layer 4, the heat insulating material layer 4 in the central part surrounded with the storing recessed groove 6 may be raised to be taken as a cushioning back rest part 7, and in this case, at the time of use, the user's back can be supported by the back rest part 7 to use the toilet stool in an easy attitude. In the toilet stool, during unuse, the heating surface 5 is stored in the storing recessed groove 6 of the heat insulating material layer 4 to reduce radiation from the heating surface and hold down the consumption of power.