PROBLEM TO BE SOLVED: To provide a mounting system for a solar module which is made lightweight as much as possible and in which the solar module can be promptly and easily mounted.SOLUTION: The mounting system comprises: a support surface forming a flat lower side of a profile rail in a cross-sectional view; first and second accommodation spaces including side openings facing directions opposite to each other; a T-shaped slot type first accommodation space including an opening facing a side opposite to the lower side of the profile rail, the opening being formed from two webs being mirror-symmetric to a virtual center plane and bent inwards in freely end portions; a first rectangular center hollow space formed from the support surface, first, second and third accommodation spaces and surrounded on all the sides; and second hollow lateral spaces disposed at both sides of the third accommodation space, adjacent to one of the first and second accommodation spaces, respectively, and surrounded on all the sides.