PURPOSE: To obtain a condensing device which is manufactured easily at a low cost, and has a high condensing ratio, by opposingly placing two through parabolic reflectors so that the respective focal lines meet at right angles.

CONSTITUTION: The first and second through parabolic reflectors 3, 4 are reflectors obtained by processing a plywood of 3mm thick to a parabolic surface, and sticking a polyester film which has vapor-deposited Al in a vacuum to approx. 8,000 thick on the surface, onto the surface of the plywood. These two parabolic reflectors 3, 4 are fixed to fixed frames 9, 10 so that the respective focal lines meet at right angles. A solar beam which has been made incident to the first through paraboilc reflector 3 are reflectors by two reflectors 3, 4 and are condensed to almost one point. In this way, a condensing device which is manufactured easily at a lost cost, and has a high condensing ratio is obtained.