PURPOSE: To obtain a comfortable sleep by incorporating integrally an electric foot- warmer in an appropriate place in the lower part of the sleeping mat which is constituted by an intermediate layer having enough softness and resiliency and an upper and a lower layer which are slightly harder than the intermediate layer and provided with a number of projections on the surface.

CONSTITUTION: The intermediate layer 2 made of very soft and resilient material such as foamed plastics is sandwiched on the upper and lower sides with the upper and lower layers 1 and 3 both made of plastics slightly harder than the material for the intermediate layer 2. The upper and lower layers 1 and 3 have a tunnel like hollow part 4 with a wave-shaped cross section, and are provided on the outer surface in the vicinity of the tops of the waves with a large number of projections 5. The upper layer 1 of thus constructed sleeping mat is engraved in the center of the lower part to form a rectangular recess 6, into which the electric foot-warmer is installed integrally.