The invention has an object to provide an endoscope which has a structure for preventing an increase in a diameter of a connection region between a channel tube and a connection member, avoiding damage on the tube without interfering with assemblability, and enabling secure assembly. To this end, the endoscope includes a tube having a single layer structure or a laminated structure made up of a plurality of layers, a branching member that branches a tubular path in an endoscope operation section and has a tube connection section to which the tube is connected, a channel locking member that sandwiches the tube with the tube connection section to thereby fix the tube to the branching member in close contact, and a fastening member that presses and brings into close contact the tube sandwiched between the tube connection section and the channel locking member, in which the channel locking member is formed so as to have a tapered portion that covers an outer circumference of the tube and have at least one flat surface on an outer circumferential face of the tapered portion.