PURPOSE: To accurately measure heat flux in a wide range from high to low by constituting a heat reception part of a plurality of elements having different heat capacities.

CONSTITUTION: When heat 5 for measurement of heat flux hits against a heat reception part, the temperature of a heat reception element 3 with a large heat capacity deviates from a proper measurement-temperature range in the case of a high heat flux and the temperature of the heat reception element 1 with a small heat capacity deviates from a proper measurement-temperature range in the case of a low heat flux. Therefore, a heat flux meter should not be used within these temperature ranges since measurement accuracy is lowered and should be used only in a proper measurement range. Thus, by constituting the heat reception part with two heat reception elements 1 and 3 with different heat capacities, measurement can be made accurately within a wide range of heat flux, where the heat capacity ratio is 1:10.