A shaft for operating a blood thrombus capturing member (2), comprises a blood thrombus capturing member (3) equipped on the distal end side thereof, and a guide tip (4) quipped at the distal end, through which a guide wire is inserted so as to be capable of relative movement, wherein the shaft (2) is flexible. Therefore, the distal end component of a blood thrombus capturing catheter can be easily guided to a vein constriction, and particularly with a branched vein, the distal end component of the blood thrombus capturing catheter can be easily guided to the targeted branch of the vein.