To provide a securing structure for a sunlight utilizing device, which is fit for setting a structure having a large size and a heavy weight such as a photovoltaic panel and a solar water heater onto a roof of a building, wherein the securing structure can prevent infiltration of rainwater into the building and exerts excellent workability.

The securing structure is formed of a bearing member 2, a metallic roof tile 1, and a gutter member 3. The bearing members is located between mutually adjacent roof tiles 4 on the roof, bears the sunlight utilizing device set thereon, and has a lower portion thereof secured to the roof. The metallic roof tile 1 is secured to the bearing member 2. The gutter member 3 has a gutter portion which stores therein rainwater infiltrating to a lower side of the roof tiles 4, and bears one of the mutually adjacent roof tiles 4 from below. Herein the metallic roof tile 1 has a cover portion 11 which covers ends of the mutually adjacent roof tiles 4, and presses the mutually adjacent roof tiles 4 downward.