A catheter includes: a conduit part having a plurality of lumens whose external diameter at a tip side thereof is constant, each of the plurality of lumens extending along an axis line inside the conduit part； and a branched part that separates axis lines of the plurality of lumens from each other at a base end side of the conduit part. At an end of the conduit part inserted into inside the branched part, an opening of each of the plurality of lumens is provided along a different axis line with each other, and a level difference is formed at the end of the conduit part.
