To provide a diaphragm barrier membrane having enough durability against stress generated by vertical movement of a valve shaft part and achieving large stroke of a valve element.

The diaphragm barrier membrane includes at the lower end of a valve shaft part joined to a valve element part closing or opening a valve seat part provided in a pipe conduit where a liquid product flows: a barrier membrane body part covering the valve shaft side and the pipe conduit inner side so as to isolate from each other; a fixed part formed at an upper part of the barrier membrane body part and fixed to a valve shaft support part including valve shaft part therein; and a valve shaft through-hole part which is formed at a central part of the barrier membrane body part, through which the valve shaft is inserted, and which is disposed below the fixed part when the valve element part closes the valve seat. In the barrier membrane body part, around the valve shaft through-hole, a first swelling part swelling downward is formed, and a second swelling part swelling upward is formed above the first swelling part.