An exhalation valve assembly (10) for a ventilator for providing ventilation to a patient is flowable in an expiratory flow direction (E) and extends along a first flow path trajectory (20). It has an upstream side respiratory gas flow path (14), a downstream side respiratory gas flow path (16) extending along a second flow path trajectory (34), a valve body (24) and a valve seat (22). A valve assembly (26) for providing a predetermined first positive respiratory gas pressure in the upstream respiratory gas flow path (14) relative to the downstream respiratory gas flow path (16). Allowing an exhaled breathing gas flow from the upstream breathing gas passage (14) to the downstream breathing gas passage (16), and allowing the downstream breathing gas flow to the upstream breathing gas passage (14). To interrupt the gas flow from the downstream respiratory gas passage (16) to the upstream respiratory gas passage (14) when a predetermined second positive respiratory gas pressure is present in the passage (16). A valve assembly (26) provided. A flow resistance structure (38) is provided inside the flow path inner wall (30a) that divides the downstream side respiratory gas flow path (16) toward the radial outer side. ) Is provided, the flow resistance structure (38) has a flow cross section of the downstream respiratory gas flow path (16) at a position where the flow resistance structure (38) is arranged. 38) compared to the downstream respiratory gas flow path (16) without. In the present invention, the flow resistance structure (38) divides the cross section of the downstream respiratory gas flow path (16) through which it can flow into no more than five structurally separated partial cross sections. And/or the flow resistance structure (38) passes through the cross section of the downstream respiratory gas flow path (16) through the second flow path (34) by 5 mm. It is specified to decrease over a length that is not shorter.患者に人工呼吸を行うための人工呼吸器のための呼気弁アセンブリ（１０）は、呼気の流れ方向（Ｅ
