Reverse osmosis membrane filter device

The purpose of the present invention is to provide a reverse osmosis filter membrane device that can reduce variations in the amount of water passing through in the direction of the axial line of water collection pipes regardless of the number or length of the water collection pipes. The reverse osmosis membrane filter device has: a water collection member that comprises at least one water collection pipe, said water collection member having a plurality of segments with each of the plurality of segments having a plurality of water collection holes; at least one filter assembly disposed around the plurality of segments, said filter assembly being formed from a filter member comprising a reverse osmosis membrane; at least one insertion tube that is disposed inside the water collection member and together with at least one sealing member defines a plurality of water transferring flow paths corresponding to the plurality of segments inside the water collection member; and a pressure adjusting device constituted so as to make pressure in at least one water transferring flow path out of the plurality of water transferring flow paths higher than one other water transferring flow path.