PURPOSE: To condense solar rays to a light-receiving member without moving a reflecting mirror by shifting the light-receiving member to the position of a focus changing by the movement of the optical path of solar rays.

CONSTITUTION: A pipe (a heat-receiving member) 21 made of stainless as a light-receiving member is disposed at the position of the focus of a concave mirror 11. Support materials 22, 23, 24 are fixed to the upper sections of the concave mirror 11, and a cylinder 25 is mounted to the upper end sections of the support materials 22, 23, 24. The cylinder 25 is provided in the longitudinal direction inside the concave mirror 11, and the pipe 21, the inside of which is supplied with a fluid, is elevated and lowered along a center line (l), and shifted to the position of the focus (the position of the focus of the concave mirror 11) changing according to the movement of the optical path of solar rays.