It comprises the steps consisting of: a) providing a filtering panel (2) having a plurality of parallel folds (3) extending between a first planar longitudinal edge and a second planar longitudinal edge (5), the filtering panel (2) comprising, at the longitudinal ends of same, a first end fold (6) and a second end fold (7), b) raising and holding the first end fold (6) and the second end fold (7) in a plane substantially parallel to the planes of the longitudinal edges (5), and c) fixing a first sealing strip (8) on the first longitudinal edge, on a first portion (9) of the first end fold (6) and on a first portion (11) of the second end fold (7), and d) fixing a second sealing strip (12) to the second longitudinal edge (5), on a second portion (13) of the first end fold (6) and on a second portion (14) of the second end fold (7). The invention also concerns a filtering element (1) that can be obtained by means of said method of production.