The disclosed catheter (10) is used as a dilation catheter threaded, for example, into cerebral blood vessels, and comprises: an outer tube (26)； and an inner tube (24) that is disposed within the outer tube (26) and through which a guidewire (20) is threaded via a tip-end aperture (24b) and a base-end aperture (24c). The outer tube (26) has, along the axial direction, at least a first region (R1) and a second region (R2) that has a higher rigidity than said first region (R1). Said outer tube (26) is configured with an aperture (22), to which the base-end aperture (24c) of the inner tube (24) connects, being provided to the first region (R1).
