To provide comfortable heating at reduced cost while making use of the immediate effect of radiant heating.

This radiant heater includes a halogen lamp 1 that produces radiant heat light; a parabolic reflector 2 for applying the radiant heat light in approximately the same direction; and a bimetal 3 for varying the relative positions between the halogen lamp 1 and the parabolic reflector 2. This is to make the relative positions between the center of emission of the halogen lamp 1 and the focus of the parabolic reflector 2 variable by means of the bimetal 3. In this way the range of application of the radiant heat light is made variable. The range of application is made variable in such a way that, as the application continues, the range is increased by the bimetal 3 relative to the range of application at the start of application of the radiant heat light. In this way when the application of the radiant heat light starts, the light is applied intensively to a narrow range to make occupants feel warmed up immediately, while increasing the range of application over time so that the range can be varied to provide heating comfort over a wide range.