A positive pressure test apparatus for fit testing a facepiece respirator having an exhalation valve, including a cover portion having a central bore with an inwardly directed shoulder at the base. A plunger is provided having a stem, a button portion on one end and a flange portion on the opposite end. The stem is situated within the central bore, the button portion extending above the surface of the cover portion in a rest position, and the flange portion extending below the inwardly directed shoulder. Bias means are located in engagement with the button portion and the shoulder for biasing the plunger from the rest position to a depressed position, wherein the button is flush with the surface of the cover portion and the flange portion seals the exhalation valve. A mounting means is provided to attach the positive pressure test apparatus to the respirator.