COMBUSTION DEVICE

PROBLEM TO BE SOLVED: To provide a combustion device capable of detecting a detection object gas even at the combustion stoppage time while reducing a consumption power.SOLUTION: A gas detection portion 14 is used for a combustion device provided with a combustion portion for burning a fuel, and detects at least any one of a leaked fuel gas or an incomplete combustion gas. The detection portion 14 includes: a gas sensitive element 20 in which an electric resistance changes in response to the detection object gas; a heater 21 for heating the gas sensitive element 20 in the temperature range where the sensitivity for the detection object gas becomes higher than the sensitivity for the gas other than the detection object gas; and a signal processing circuit 24 having a function to control electrical-conduction to the heater 21 and the function to detect the detection object gas from an electric characteristic value of the gas sensitive element 20. At the combustion stoppage time, the signal processing circuit 24 is electrically conducted to the heater 21 and intermittently provides a heating period for heating the gas sensitive element 20 in the temperature range, and the gas sensitive element 20 performs the detection of the detection object gas from the electric resistance of the gas sensitive element 20 in a heated state.