Combustible gas detection device

A combustible gas detection device comprising:

• a heat generation resistor disposed in an object atmosphere where its resistance changes with its own temperature;
• an energization control section which controls the switching of an energization state of the heat generation resistor every time a predetermined time period elapses such that the heat generation resistor alternately has resistances corresponding to two predetermined temperatures set in advance;
• a temperature measurement resistor disposed on a substrate having the heat generation resistor disposed thereon where its resistance changes with an environmental temperature which is the temperature of the object atmosphere;
• a gas concentration computation section which calculates a concentration of a combustible gas contained in the object atmosphere by using a voltage generated across the heat generation resistor which is detected when electricity is supplied to the heat generation resistor by the energization control section, and using the environmental temperature based on a voltage change which occurs as a result of a change in the resistance of the temperature measurement resistor, wherein
• the period of time has a length determined in advance such that a change in the environmental temperature which occurs when the energization control section switches the energization state of the heat generation resistor falls within a range of 0.5° C.