A guidewire comprising: a core shaft; an outer coil surrounding a front side portion of the core shaft; an inner coil (50, 150) constituted by at least one strand wound, which surrounds the front side portion of the core shaft in the outer coil; a front end joint joining a front end of the outer coil and a front end of the inner coil (50, 150) to the front end of the core shaft; an outer rear end joint joining a rear end of the outer coil to the core shaft; and an inner rear end joint joining a rear end of the inner coil (50, 150) to the core shaft further on a front side than the outer rear end joint, characterized in that the outer coil has a tapered coil portion constituted by at least one strand wound to decrease an outer diameter toward a front end of the core shaft, an outer diameter of the inner coil (50, 150) on a front side arranged on a front side of the tapered coil portion is smaller than an outer diameter on a rear side, wherein the inner coil (50, 150) includes: a front inner coil portion (51, 151) which is arranged on a front side of the inner coil (50, 150) and constituted by at least one strand wound such that the front inner coil portion (51, 151) has an approximately constant outer diameter; and a rear inner coil portion (55, 155) which is arranged on a rear side of the inner coil (50, 150), constituted by at least one strand wound such that the rear inner coil portion (55, 155) has an approximately constant outer diameter, and which has a larger outer diameter than the outer diameter of the front inner coil portion (51, 151), and wherein a diameter of the strand constituting the front inner coil portion (51, 151) is smaller than a diameter of the strand constituting the rear inner coil portion (55, 155). a core shaft; an outer coil surrounding a front side portion of the core shaft; an inner coil (50, 150) constituted by at least one strand wound, which surrounds the front side portion of the core shaft in the outer coil; a front end joint joining a front end of the outer coil and a front end of the inner coil (50, 150) to the front end of the core shaft; an outer rear end joint joining a rear end of the outer coil to the core shaft; and an inner rear end joint joining a rear end of the inner coil (50, 150) to the core shaft further on a front side than the outer rear end joint, characterized in that the outer coil has a tapered coil portion constituted by at least one strand wound to decrease an outer diameter toward a front end of the core shaft, an outer diameter of the inner coil (50, 150) on a front side arranged on a front side of the tapered coil portion is smaller than an outer diameter on a rear side, a front inner coil portion (51, 151) which is arranged on a front side of the inner coil (50, 150) and constituted by at least one strand wound such that the front inner coil portion (51, 151) has an approximately constant outer diameter; and a rear inner coil portion (55, 155) which is arranged on a rear side of the inner coil (50, 150), constituted by at least one strand wound such that the rear inner coil portion (55, 155) has an approximately constant outer diameter, and which has a larger outer diameter than the outer diameter of the front inner coil portion (51, 151), and wherein a diameter of the strand constituting the front inner coil portion (51, 151) is smaller than a diameter of the strand constituting the rear inner coil portion (55, 155).