PURPOSE: To enable an efficient transferring of heat to a user from a heat radiation plate before a room is warmed by a method wherein heat generating surfaces of the heat radiation plates are alternatively changed in their orientations and concentrated toward the user.

CONSTITUTION: A connecting pipe 1 comprises an upper connecting pipe and a lower connecting pipe which are parallel to each other. A plurality of heat radiation plates 2 are fixed to the connecting pipe 1 while being crossed at a right angle thereto. Hard-igniting oil circulated in the connecting pipe 1 and the heat radiating plates 2 and a heater for use in heating oil stored in the connecting pipe 1 are provided. The heat radiation plates 2 are bent at an angle of about 30° at a bending line 2a and bent back at an angle of about 30° in a reverse direction at the bending line 2b set at a symmetrical position of the former bending line 2a in respect to the connecting pipe 1. Each of the adjoining heat radiation plates forms a plane symmetrical shape and a plurality of heat radiation plates are equally spaced apart and fixed in such a way that they serve as the heat radiation plates having the same shape for every one of them. Since the heat radiation planes of the heat radiation plates 2 are formed in a cone-like manner to a user in double-stepped manner, the radiation heat is collected forwardly and the heat supplied to the user can be increased.