In a securing unit including first frames for holding the end sides of a solar cell and a securing tool, the securing tool includes a base member that is secured to an installation face, a stand that is erected from the base member, a shaft that has an external thread and is held by the stand in a state in which a movement in the axial direction is restricted, and a holder that holds the first frame by inserting a lateral side extended portion into a slit of the first frame and moves up and down relatively to the stand by screwing internal threads formed in the holder together with the external thread of the shaft.