PURPOSE: To perform a comfortable heating with an energy saving even in such a space where a person is present for a relatively short period of time by a method wherein a radiation surface control is carried out in response to a sensed data detected by a human body surface temperature sensing mean: and an occupant position sensing means.

CONSTITUTION: In the event that no person is present in a room 5, a presence of a person in the room 5 is not detected by a human body surface temperature sensing means 1, resulting in that a radiation surface 3 at an initial starting position is kept OFF and a radiation heating is not carried out. In the event that there is a person in the room 5, the human body surface temperature sensing means 1 detects that there is a person in the room 6 and further detects the human body surface temperature. In the even. that the human body surface temperature is 33°C or above a radiation panel constituting a radiation surface 3 is turned off. However, in the event that the human body surface temperature is 33°C or below a distance between it and a human body is calculated by the occupant position sensing means 2 to detect a human body position. The most appropriate radiation surface of a plurality of divided radiation surfaces 3a, 3b and 3c is selected in response to the detection of the human body position, the radiation panel selected and constituting the radiation surface is turned on to perform a radiation heating.