Provided is a catheter capable of preventing an end portion of a retrograde guide wire from straying into a base end side shaft.The catheter 1 according to an embodiment of the present invention includes a mesh member 110 having a tubular shape and radially expandable and contractable, a first hollow shaft 120 connected to a base end of the mesh member 110, a front end tip 130, and a core wire 150, in which the first hollow shaft 120 includes a front end side shaft 121 having a front end connected to the base end of the mesh member 110 and a base end side shaft 123 having a front end connected to a base end of the front end side shaft 121, an opening 126 is provided at the base end of the front end side shaft 121 in a connection portion 125 between the front end side shaft 121 and the base end side shaft 123, and a sealing member covering an outer periphery of the core wire 150 and allowing the core wire 150 to be slidable thereinside is arranged at the front end of the base end side shaft 123 in the connection portion 125.
