PROBLEM TO BE SOLVED: To provide a basket retainer easily capturing a concretion or the like in a basket and capable of securing the opening width of the basket even in a narrow lumen.SOLUTION: A basket retainer 1 includes: a long flexible sheath 2 an operation wire 3 extractably/retractably inserted in the sheath 2 and a basket part 4 that is provided at a distal end of the operation wire 3, formed by binding tip ends and rear ends of a plurality of elastic wires 5a-5d into a substantially basket shape, and storingly retains a recovery object in the inside thereof. The basket retainer 1 projects/retracts the basket part 4 with respect to the distal end of the flexible sheath 2 by extractingly/retractingly operating the operation wire 3 and elastically contracts or expands the basket part. In the expanded state, a maximum diameter part 50 of the basket part 4 is disposed at a rear end side with respect to an axial central position of the basket part 4.
