To provide an air heating device capable of efficiently supplying the superheated air by burning a hydrogen-oxygen mixed gas and sucking the same by a suction pump.

An inner pipe 52 of a burner 10 is kept into contact with a suction opening 13 of the suction pump 12, and the suction opening 13 of the suction pump 12 is entirely covered by an outer pipe 50 as shown in a drawing 10. Further A central portion of the suction pump 12 is covered by the inner pipe 52 joined to the outer pipe 50. In this state, a gas is supplied from a hydrogen-oxygen mixed gas generating device, the gas is passed through a burner main pipe 34, a burner chip 31 and a plurality of nozzles 30, and ignited by an ignition plug 53. Here, flame and the air in the burner pipe 10 are sucked by the suction pump 12 and the heated air 21 is efficiently discharged by operating the suction pump 12.