A guidewire includes a core shaft having a first tip portion and a first rear end portion, and a coiled body having a second tip portion and a second rear end portion and wound around the outer circumferential surface of the first tip portion. The core shaft further includes a first cylindrical portion, a second cylindrical portion, and a third cylindrical portion. The second cylindrical portion has an outer diameter larger than an outer diameter of the first cylindrical portion and smaller than the maximum diameter of the coiled body, and the third cylindrical portion has an outer diameter larger than an outer diameter of the second cylindrical portion and smaller than the maximum diameter of the coiled body.
