A photovoltaic power generation system comprising: a solar cell module comprising a solar cell panel and a frame disposed at a periphery of the solar cell panel, wherein a fixing hole is formed at the frame (14, 40), and a first fastening member is coupled to the fixing hole, a support member for supporting the solar cell module, wherein the photovoltaic power generation system further comprises a second fastening member connected to the support member and fastened to the first fastening member, and the first fastening member and the second fastening member fasten the solar cell module and the support member to each other, characterized in that the first fastening member comprises a nut portion undetachably fixed to the frame, the first fastening member comprising: the nut portion undetachably fixed to the frame (14, 40), wherein the nut portion is disposed at a first surface of the frame and has a larger outer diameter than a diameter of the fixing hole, a connecting portion extending from the nut portion and configured to be disposed within the fixing hole, and a rivet portion disposed at a second surface of the frame (14, 40) while having a larger outer diameter than the diameter of the fixing hole, wherein the support member is positioned on the frame and the rivet portion of the first fastening member, and wherein the second fastening member is disposed on the support member, penetrates the support member, reaches threads at an inner surface of the first fastening member inside the fixing hole, and is fastened to the threads, wherein the first fastening member constitutes a lock nut, and wherein a thread of the lock nut has a deformed shape, the thread of the lock nut has slits, the thread of the lock nut includes portions spaced from one another and radially protruded, the lock nut comprises a double nut including a lower nut having an eccentric upper sliding surface and an upper nut having a concentric lower sliding surface that are threadedly coupled, or a resin insert of a plate spring is inserted into the thread of the lock nut. a solar cell module comprising a solar cell panel and a frame disposed at a periphery of the solar cell panel, wherein a fixing hole is formed at the frame (14, 40), and a first fastening member is coupled to the fixing hole, a support member for supporting the solar cell module, wherein the photovoltaic power generation system further comprises a second fastening member connected to the support member and fastened to the first fastening member, and the first fastening member and the second fastening member fasten the solar cell module and the support member to each other, characterized in that the first fastening member comprises a nut portion undetachably fixed to the frame, the first fastening member comprising: the nut portion undetachably fixed to the frame (14, 40), wherein the nut portion is disposed at a first surface of the frame and has a larger outer diameter than a diameter of the fixing hole, a connecting portion extending from the nut portion and configured to be disposed within the fixing hole, and a rivet portion disposed at a second surface of the frame (14, 40) while having a larger outer diameter than the diameter of the fixing hole, the nut portion undetachably fixed to the frame (14, 40), wherein the nut portion is disposed at a first surface of the frame and has a larger outer diameter than a diameter of the fixing hole, a connecting portion extending from the nut portion and configured to be disposed within the fixing hole, and a rivet portion disposed at a second surface of the frame (14, 40) while having a larger outer diameter than the diameter of the fixing hole, wherein the support member is positioned on the frame and the rivet portion of the first fastening member, and wherein the second fastening member is disposed on the support member, penetrates the support member, reaches threads at an inner surface of the first fastening member inside the fixing hole, and is fastened to the threads, wherein the first fastening member constitutes a lock nut, and wherein a thread of the lock nut has a deformed shape, the thread of the lock nut has slits, the thread of the lock nut includes portions spaced from one another and radially protruded, the lock nut comprises a double nut including a lower nut having an eccentric upper sliding surface and an upper nut having a concentric lower sliding surface that are threadedly coupled, or a resin insert of a plate spring is inserted into the thread of the lock nut.