PURPOSE: To elevate the reliability of a heat flow meter by checking the action of a heat flow meter and inspecting the sensitivity thereof properly generating heat from a heat generating body provided near the element for measuring the temperature difference between the surface and the back of a heat resistor.

CONSTITUTION: Thermopiles 12 are mounted on the surface 11a and the back 11b of a heat resistor 11 to measure the temperature difference between the surface and the back thereof. A hot contact 12a of the pile 12 is arranged on the surface 11a of the heat resistor 11 and a cold contact 12b thereof on the back 11b thereof while an air insulation sheet 13 is provided tightly on another surface of the heat resistor 11 and a heat plate 14 is provided tightly on the surface of the sheet 13 opposite to the heat resistor 11. When power is fed in a pulse manner to the heater plate 14 from a power source 17, a peak appears on a recording paper of a recorder 18. Based on the peak, a heat flow density is determined and compared with a heat generated in the heater plate 14 to inspect the sensitivity of the heat flow meter.