Disclosed are an optical-path changing apparatus and a light radiating apparatus. The optical-path changing apparatus includes a light scattering member such as a light reflecting member, and a guide member for guiding the light scattering member. The direction of light scattered by the light scattering member is substantially constant during movement of the light scattering member guided by the guide member. The light radiating apparatus includes a fluorescent member, a guide member for guiding the fluorescent member, and a light emitting device for irradiating with light the fluorescent member moving along the guide member.