There is provided an endoscope that can smoothly move forward a treatment tool to a connecting pipe from a treatment tool-inserting tube in an up-angle form. A fixing sleeve 90 that is fitted outward on a connecting portion between a connecting pipe 86 and a treatment tool inserting tube 88 for fixation of the connecting portion comprises a cylindrical sleeve body 90A, an arc-shaped portion 90B that is connected to a proximal end side of the sleeve body 90A, is formed to be coaxial with a sleeve center axis of the sleeve body 90A and has a center angle smaller than 180°, and a projection portion 90C that is formed along a peripheral direction of the sleeve center axis on an inner peripheral surface in the arc-shaped portion 90B in a radial inside of the sleeve center axis. A part 88A of the treatment tool inserting tube 88 is flexibly deformed in a convex shape by the projection portion 90C, and the part 88A thereof is supported by the projection portion 90C.
