The combustion heater 110, heating plate 126 and the placement plate 120, and the outer peripheral wall 122 disposed along the outer periphery of the heating plate and disposed plate disposed opposite to the heating plate and the heating plate, the arrangement plate and the outer wall at the same time, also arranged opposite to the heating plate and disposed plate within the space surrounded by, and form an introduction section 134 by the air gap between the placement plate and a partition for forming a 138 portion drawn by the air gap between the heating plates disposed in the plate 124 and a heating plate, arranged plate and a space surrounded by the outer peripheral wall, and burn the fuel gas introduced from the inlet, the combustion chamber 136 to draw toward the derivation of the exhaust gas generated by the combustion provided, and the partition plate is provided with a concave-convex portion 146 with the irregularities in the thickness direction.