Abstract: A guidewire is disclosed, which includes a core member that is an elongated member having flexibility, and a coil member that is disposed so as to cover a distal portion of the core member and that is formed by helically winding a strand, the coil member being fixed to the core member in a distal portion of the guidewire. The core member includes a body portion in a proximal portion thereof and a flat portion in the distal portion thereof. At least one projection is formed on at least one of two side surfaces of the flat portion extending in a longitudinal direction, the at least one projection projecting into a space between adjacent turns of the strand and being in contact with the strand.

Abstract: A guide wire is disclosed, which includes a core portion formed of an elongated object having flexibility, in which the core portion includes a main body portion formed on a proximal side, a flat plate portion formed on a distal side, and a transition portion which connects the main body portion and the flat plate portion, and in which at least one groove portion extending in a direction different from a length direction is formed on a slope of the transition portion in the length direction. In addition, the guide wire includes a coil portion disposed so as to cover the distal side of the core portion.