Provided is a hollow sound damper as a miniaturized sound damper which preserves a sound damping function and has a space in a tube (A) having a noise and whereby air is supplied or evacuated, said space having a larger cross-section area than the tube (A). On one lateral wall of a tube (B) on the opposite side from a noise source which emits the noise, said tube (B) extending from the hollow sound damper and having at least two or more ports for making the air flow in or out.本發明提供一種中空型消音器，該中空型消音器是作為維持消音性能、小型化的消音器，且於供給具噪音之氣體或排氣之配管A的途中，具有相較於該配管A，剖面積大的空間，其中，於與產生該噪音之噪音源相反側，從該中空型消音器延伸之一邊的配管B側面，具有至少2個以上之用以使氣體流入或流出的端口。
