A channel tube 26 inserted into an insertion portion 5 of an endoscope includes: a rear side tube 26B including, on a part of an outer surface thereof, a helical-shaped groove 8 1 B and a front side tube 26A a connecting pipe 91 for connecting one end of the rear side tube 26B and one end of the front side tube 26A and a coil 34B wound on the groove 81B of the rear side tube 26B. The rear side tube 26B is connected to the connecting pipe 91 at a part RR where the groove 81 B is formed and the coil 34B is not wound.
