To quickly transmit the temperature of a heat medium to the external surface of a cold heat cushion sheet by a thermocompression bonding of aluminum-laminated films on both sides of a sponge sheet to circulate the heat medium through a path partitioned by the sponge sheet and the aluminum- laminated films.

A zigzagged groove is formed in a sponge sheet 1 and both sides of the sponge sheet 1 are bonded being sandwiched between aluminum- laminated films 2. Then, the sponge sheet 1 and the aluminum-laminated film 2 are thermally bonded closely by fusing them together. In this manner, a path 4 with a rectangular cross section is formed surrounded by the sponge sheet 1 and the aluminum-laminated film 2. Then, a heat medium is circulated through the path 4. This enables quick transmission of the temperature of the heat medium to the external surface of the thermal cushion sheet obtained.