To enhance exposure efficiency and realize size reduction, by shortening exposure time compared with a case where magnified light is irradiated to the whole of an exposed surface.

The light of a lamp 26 is guided to an exposure head 31 by a flexible light guide body 30, the light is condensed by the exposure head 31 and irradiated to an exposed surface 12, and the exposure head 31 is caused to move and scan along the exposed surface 12 by a moving means 32. The illuminance of the light irradiated from the exposure head 31 is measured by a measuring part 35, and the moving speed of the exposure head 31 is controlled by a control part 24 according to the measured illuminance of the light.