A calculus retrieving device for retrieving calculus in a renal pelvis includes an elongated member positionable in and movable along a ureter, and having a lumen opening at the distal end of the elongated member. A tubular member is movably positioned inside the elongated member and includes a lumen which opens to a discharge nozzle at a distal end of the tubular member. A space exists between the elongated member and the tubular member to receive a first fluid, and an expandable renal cover part fixed to the elongated member is positionable in the renal pelvis. The renal cover part interior communicates with the space so that the first fluid flows into the renal cover part to expand the renal cover part into covering relation to one part of the renal pelvis while another part of the renal pelvis containing the calculus is not covered by the renal cover part.