To efficiently heat air in a hermetically sealed container by providing a heating device with a heater, a heating unit provided with a temperature regulator for regulating the temperature of the heater and the hermetically sealed container to which the heater is attached.

This heating device 30 consists of the hermetically sealed container 32 whose inside can be hermetically sealed and a heating part 34 for heating the inside of the container 32. In addition, the container 32 is constituted of a housing part 35 for housing a matter to be heated inside and a lid 37 for closing the opening part of the upper surface of the part 35. the part 35 is formed to be nearly rectangular in the view of a plane, and a wall surface 35a and a bottom surface 35b covering the surrounding of the part 35 are formed in double structure. Thus, it is suitable that heat insulating effect is improved and heating efficiency is improved. In addition. The surface 35a and the surface 35b formed in double structure can additionally improve a heat insulating effect by filling a heat insulating material 29 in a space between the walls formed in double structure.