This guide wire gripping unit is provided with: a sheath； a linear member extending along the longitudinal axis of the sheath； an operation part that moves the linear member along the longitudinal axis； a gripping member having a contact surface having a peripheral edge surrounded by a distal end, a proximal end, and a pair of side ends； and a support part connected to the linear member and fixed to one of the pair of side ends. A gap between the contact surface and an outer peripheral surface of a sheath distal end portion is open at the other side of the distal end, the proximal end, and the pair of side ends of the contact surface so that the guide wire is accommodated in the gap or released from the gap from the other of the pair of side ends. The gripping member is moved to a position facing the outer peripheral surface according to the movement of the linear member and the support part, whereby the guide wire disposed in the gap is gripped between the contact surface and the outer peripheral surface.
