A heat generator includes a heat generating member for generating heat flow, a temperature compensating member, and a heat flow compensating circuit connected between the heat generating member and the temperature compensating member. The heat generating member includes a heat export face and a heat insulation face. The temperature compensating member includes a temperature compensating face facing the heat insulation face. The circuit is capable of controlling heat generated by a thermoelectric resistor of the temperature compensating member to cause the temperature of the temperature compensating face to be equal to the temperature of the heat insulation face, which results in the heat energy of the heat flow exporting out from the heat export face of the heat generating member to be substantially equal to the heat energy of the heat generated by the heat generating member.