A suction catheter does not require a major device and has a flexibility enabling the catheter to be adopted for a bent blood vessel as the catheter follows a largest suction lumen and a guide wire, and therefore the catheter can be easily transported to a treatment portion. A suction catheter is structured such that the tip portion of a main shaft is obliquely cut, the tip portion of a guide wire shaft is positioned at the tip most portion of the main shaft or is projectingly positioned at a place closer to the tip side of the main shaft than the tip most portion, and the expressions of 0.5 ≦ L2/L1 and L2 - L1 ≦ 5 mm are simultaneously satisfied with L1 the length at the portion where the main shaft is obliquely cut taken along the longitudinal axis of the catheter and L2 the length from the end on the user side of the guide wire shaft to the tip most portion of the main shaft.
