The invention concerns a filtration device comprising a manifold (3) providing fluid connection and mechanical connection comprising a clamping plate (4) movably mounted relative to the manifold (3) and adapted to compress at least one cassette (2) against the manifold (3), means for driving and guiding the clamping plate comprising a rod (6) extending between the manifold (3) and the plate (4), an actuator provided with a body and a member moveable relative to the body, which member is adapted to move through a predetermined travel between an extended position and a retracted position, the body being carried by the manifold (3), and the member carrying the rod (6) and driving the plate (4) via the rod (6) to a clamped position in which the member is in an intermediate retracted position in which it has moved through a shorter travel than the predetermined travel relative to its extended position.