PURPOSE: To enable high preciseness measurement, by constituting a heat flowline due to a heat transfer body between a heating furnace and a heat transfer plate while controlling the supply electric power to a heater provided in contacted relation to the heat transfer plate so as to bring the temp. difference between two points on the heat flowline to zero.

CONSTITUTION: A specimen 2 is placed on a heat transfer plate 3 which is, in turn, spaced apart from the inner wall of a furnace 1 at the peripheral edge thereof and the supply of heat from the furnace 1 is performed through a projection piece 3a. That is, the projection piece 3a forms a spacially limited heat flowline. In this case, a plane heater 4 is adhesively provided to the back surface of the heat transfer plate 3 and electric power supplied to the plane heater 4 is controlled so as to bring the outputs of thermocouples T1, T2 to zero. By this mechanism, because the heat amount injected to the specimen can be detected without using a reference substance, measuring operation is simple and high preciseness measurement can be performed.