A guide wire is disclosed, which includes a wire main body that has flexibility a distal end member that is fixed to a distal end portion of the wire main body and a tubular member that is arranged closer to a proximal end side than the distal end member, and on an outer circumference of the wire main body. The tubular member can be configured such that the longitudinal entirety of the tubular member is not fixed to the wire main body. The tubular member can be provided such that a distal end portion of the tubular member is not fixed to the distal end member. A proximal-end side thickness reduction portion with a wall thickness decreasing toward the proximal end side is provided in a proximal end portion of the tubular member.