More than two damping chambers 2A to 2C), a communicating pipe (6) for intercommunicating the damping chambers (2A, 2B) and another communicating pipe (7) for intercommunicating the damping chambers (2B, 2C) are provided. Both ends of the communicating pipes (6, 7) are closed by an end plate (9) and the respective damping chambers (2A to 2C) and inside of the communicating pipes (6, 7) are intercommunicated by communicating holes (8A) on an outer circumference of the communicating pipes (6, 7). Exhaust gas flows from the damping chamber (2A) to communicating holes (8A1), inside of the communicating pipe (6), communicating holes (8A2), the damping chamber (2B), communicating holes (8A3), inside of the communicating pipe (7), communicating holes (8A4), and the damping chamber (2C), thus damping exhaust noise by repeated effective contraction and expansion.