A catalytic combustion device of the type including a catalyst for oxidation of a fuel vapor and air, and an ignition heater for initiating oxidation on the catalyst is disclosed. The device comprises a tubular first member carrying thereon the catalyst for supplying the fuel vapor to the catalyst, and a tubular second member disposed in the first member defining therein a passageway for the fuel vapor, the second member being secured at its one end thereof to the first member so as to constitute a thermostatic element for controlling the rate of gas flow by means of the difference in thermal expansion between the first and second members.