A guidewire includes a core shaft (10) having a first tip portion (11) and a first rear end portion (12), and a coiled body (20) having a second tip portion (21) and a second rear end portion (22) and wound around the outer circumferential surface of the first tip portion (11). The core shaft (10) further includes a first cylindrical portion (13), a second cylindrical portion (14), and a third cylindrical portion (15). The second cylindrical portion (14) has an outer diameter (D2) larger than that (D1) of the first cylindrical portion (13) and smaller than the maximum diameter (Dc) of the coiled body (20), and the third cylindrical portion (15) has an outer diameter (D3) larger than that (D2) of the second cylindrical portion (14) and smaller than the maximum diameter (Dc) of the coiled body (20).
