A device for filtering a stream of water in a channel (2), includes: a wall (6) adapted to be mounted in the channel and including a through-opening, a filter member (10) mounted on the wall opposite the through-opening and including a filter surface projecting relative to the wall, the filter surface having a larger area than would have a flat filter surface fitted in the through-opening, the filter member including retaining members face to face with the filter surface for retaining the bodies that do not pass through the surface, a suction device disposed facing the retaining members, and elements for driving the filter member and/or the suction device in a relative movement of one in relation to the other such that the suction device is successively brought face to face with each retaining member.