To ensure an efficient, safe and economical use of pool by constructing the same with a structure in which metal fittings supporting a lane rope can be detouchably engaged with a pool edge, and thereby enablying stepless change of the width of lane according to purposes.

A fixing bolt 5 is threadingly fitted in a threaded hole 8 in a perpendicular part of a lane rope support metal fitting on the side of a pool, and a pressing part 6 is mounted at the tip of the bolt 5 so that it may not turn simultaneously with the turn of the bolt 5. A horizontal part 1 of the fitting is brought into contact with a desired upper surface of pool circumferential edge at the position where a lane rope is extended, with the part 6 fully pulled out, and with a side of a drain groove 11 on the pool side a perpendicular part 3 of the fitting on the groove 11 side is brought into contact. Then, the bolt 5 is pushingly driven to bring the part 6 mounted at the tip of the bolt 5 into pressure contact with an inner wall 10 of pool. Further, the bolt 5 is fastened firmly with a nut 7 after the threaded-into position of the bolt 5 is confirmed.