FIELD: chemistry. SUBSTANCE: disclosed is a group of inventions intended for determining filtering properties, specifically: fineness (nominal and absolute) filtration and capacity (nominal and specific consumption of filtrate), porous metal materials (filters) on a molten mixture of halogenides of alkali metals, in particular sodium and potassium chlorides of equimolar composition with content of unmelted fine oxides. Device comprises working metal chamber (6) with indicator electrode (7), where filtered medium (3) and tested porous metal material, as well as quartz cell (5) for filtrate (1) are placed. Cell (5) and chamber (6) are placed in metal container (4) with nozzles to maintain inert atmosphere. Fugitive state of filtered medium (3) is maintained by heating elements (8). Inert atmosphere is created using gas equipment (9). Method of determining filtering properties involves three steps. At first filter (2) is installed, providing inert atmosphere and heating of filtered medium (3). At the second stage filtration process is carried out with maintenance of filtered medium temperature (3) and working pressure to filter (2). Filtrate (1) is collected and after the tank with filtered medium (3) is emptied, the process is completed and the vessel with filtrate (1) is removed. At the third stage productivity and fineness of filtration of tested filters are determined. EFFECT: invention enables to determine filtration properties of porous metals based on a molten mixture of sodium and potassium chlorides of equimolar composition with content of unmelted fine oxides.