A guide wire includes a first wire disposed on the distal side of the guide wire and a second wire disposed on the proximal side from the first wire. The first wire and the second wire are joined to each other by welding. A welded portion formed by welding has a projection projecting in the outer peripheral direction. The height of the projection may be in a range of 0.001 to 0.3 mm. The first wire may be made from a superelastic alloy, and the second wire be made from a stainless steel. The first wire and the second wire are welded to each other by a butt resistance welding process. Such a guide wire has a high joining strength between the first wire and the second wire, to thereby improve the operationality.