Provided is a guide wire, which comprises a lengthy wire body, and a marker disposed in at least the tip side portion of the wire body all over the circumference and having a function to indicate the position of the wire body in a living body. The marker is formed into a lattice shape as a whole by causing a first filament portion and a second filament portion to intersect with each other at a plurality of portions. Moreover, the intersecting portions of the first filament portion and the second filament portion are formed in plurality in the marker. Noting a predetermined one of those intersecting portions, therefore, the predetermined intersecting portion looks, as if it moves radially of the guide wire, when the guide wire is turned on its axis. Thus, it is possible to confirm reliably that the guide wire has been turned.
