An improved filter mounting mechanism for laboratory work cabinets, especially biological safety cabinets, enables simple and quick removal and replacement of a filter supported in the cabinet housing between a work chamber and a filtration chamber. The filter mounting mechanism includes a stationary filter support surface between the work chamber and the filtration chamber, and a filter clamping surface movable toward and away from the filter support surface between a clamping position relatively proximal to the filter support surface for holding the filter in an operational disposition against the filter support surface and an installation position relatively distal to the filter support surface for permitting insertion and removal of the filter between the filter support and clamping surfaces. An extensible and retractable linkage mechanism, e.g., a scissors mechanism, is connected to the filter clamping surface for selectively actuating movement of the clamping surface between the clamping and installation positions.