To improve an achievement coefficient of a heat/cold reserving apparatus by effectively utilizing heat, in a type which keeps coffee or the like left half-finished hot or cool using a thermoelement.

The pressure in a heat pipe 4 buried into a cup receptacle 2, having a cup 1 with coffee therein put thereon, is controlled with bellows 8, being stretched by an actuator 9 to perform a heat flow switch function. When the temperature of the cup 1 is higher than that of heat reserved, the pressure in the heat pipe 4 is raised to lower the level of heat transmission between the cup and a thermoelement 3, thereby preventing heat from escaping to the thermoelement from the cup 1. When the temperature of the cup is lower than that of heat reserved, the pressure in the heat pipe 4 is lowered to keep the cup 1 hot by heat from a joint part 3a on the heating side of the thermoelement 3. The pressure ho in a heat pipe 14 buried into a drink container receptacle 12, having a drink container 11 put thereon, however, is controlled with bellows 18 being stretched by an actuator 19. When the temperature of the drink container 11 is lower than that of cold reserved, the level of heat transmission between the container, and a thermoelement 13 is lowered while it is raised, when the temperature is higher than that of cold reserved.