A guide wire for medical treatment includes a straight-line shaped proximal section and a distal section which is continuous with the distal side of the proximal section and whose most distal portion faces toward the proximal direction. The distal section includes a curved portion continuous with the proximal section and a distal portion continuous with the distal side of the curved portion, the proximal section and at least a portion on the proximal side of the curved portion continuous with the proximal section are positioned on an identical plane, and the distal portion is extended toward a direction backing away from the plane and includes the most distal portion in a section of a direction to which the curved portion is curved with respect to an plane n an axis core of the proximal section orthogonal to the plane.
