Exhaust device of engine

An exhaust device of an engine, the exhaust device comprising:

• an exhaust pipe through which an exhaust gas from the engine flows;
• and a muffler provided on a downstream side of the exhaust pipe,
• the muffler including
• a casing,
• a first expansion chamber, a second expansion chamber, and a third expansion chamber separately formed in the casing, and
• a first communication pipe, a second communication pipe, and a third communication pipe provided in the casing, wherein
• the exhaust pipe is connected to the first expansion chamber, the first expansion chamber communicates with the third expansion chamber via the first communication pipe, the first expansion chamber communicates with the second expansion chamber via the second communication pipe, the second expansion chamber communicates with, via the third communication pipe, another chamber separately formed from any of the first expansion chamber, the second expansion chamber, and the third expansion chamber outside or inside the casing, and the third expansion chamber does not communicate with an outside of the third expansion chamber except that the third expansion chamber communicates with the first expansion chamber via the first communication pipe.