The present invention aims to provide a silencer which is excellent in maintainability and small in size and light, and a breathing assistance device. A blower (20) for generating pressurized air to apply the pressurized air from the mounting portion (70) to be worn by the patient to the airway of the patient, wherein the blower (20) A muffler (30) which is inserted into a flow channel for guiding the pressurized air to a patient to reduce the sound generated by the therapeutic device, the muffler being provided outside the housing that houses the blower (20) .本発明は、メンテナンス性に優れ小型軽量な消音器と、呼吸補助装置の提供を目的とする。送風機(20)で加圧空気を生成して患者が装用する装着部(70)から前記患者の気道に前記加圧空気を印加する治療器(80)に設けられ、前記送風機(20)から前記患者に前記加圧空気を導く流路へ挿入して、前記治療器が発生する音を軽減する消音器(30)であって、前記送風機(20)を収納する筐体の外に設けられることを特徴とする。
