Abstract: This invention relates to a muffler and in particular to one including a high frequency chamber, a first exhaust pipe connected between an engine and the high frequency chamber, a second exhaust pipe disposed within said high frequency, an intermediate frequency chamber connected with the other end of the second exhaust chamber, a third exhaust pipe disposed within the intermediate frequency chamber, a low frequency chamber connected with the other end of the third exhaust pipe, and a tubular pipe disposed within the low frequency chamber, whereby the noise will be effectively suppressed without decreasing the flow rate of the exhaust gas and the output power of the engine.