An exhaust mechanism includes: an exhaust pipe configured to circulate exhaust gas from an engine; a first outer pipe disposed along the exhaust pipe on an outer periphery of the exhaust pipe; a second outer pipe disposed along the first outer pipe on an outer periphery of the first outer pipe; a pair of intermediate members disposed on the outer periphery of the exhaust pipe, fixed to respective inner peripheral surfaces of a first end portion and a second end portion of the first outer pipe, and being lower in thermal conductivity than the exhaust pipe. A vacuum layer is provided between the first outer pipe and the second outer pipe. At least one of the intermediate members is configured to slide in an axial direction of the exhaust pipe.