Abstract: Respirator of the mask-type covering the nose and mouth of a wearer to protect him from environments containing air-borne obnoxious particles and gases having a combination of a compressed air inlet regulator on the face of the mask, internal baffling which directs inlet air downwardly past the nose of the wearer, and spaces at the mask's sides in the wearer's cheek area and below his mouth to effect an air flow through and out of the mask in a downward direction with little annoyance to the wearer, to assist in exhausting exhaled breath from the mask, and to form an "air-curtain" at the mask's outlet spaces that prevents entry into the mask of obnoxious particles and gases. The mask is further adapted for quick coupling and uncoupling to and from supply lines of air under pressure and for use with air supply lines of widely varying supply pressures.