Provided is a combustion heater (100), which includes a heating plate (118), a layout plate (120) disposed opposite to the heating plate, an annular outer circumferential wall (122) interposed between the heating plate and the layout plate, clipping parts (136) configured to sandwich the heating plate, the layout plate, and the outer circumferential wall so that at least one of the heating plate and the layout plate is allowed to expand in an extending direction thereof, a partition plate (124) disposed between the heating plate and the layout plate, a combustion chamber (126) disposed inside the outer circumferential wall along the outer circumferential wall, an inflow passage (128) configured to flow fuel gas into the combustion chamber using the layout plate and the partition plate as a lateral wall thereof, and an outflow passage (130) configured to discharge exhaust gas from the combustion chamber to an outside using the heating plate and the partition plate as a lateral wall thereof, and to preheat the fuel gas using heat of the exhaust gas via the partition plate. According to the combustion heater, thermal fatigue caused by repetition of heating and cooling can be suppressed.