Abstract: The invention relates to a method and a device for treating surfaces of metallic strip material (1), especially for pickling rolled material, in a treatment channel (2), with a pickling medium (3) containing acid. Jets (4) are set in the direction in which the strip is transported (5) at the entrance to the channel (2a) and in the opposite direction that in which the strip is transported at the exit of the channel (2b). The aim of the invention is to produce a closed liquid film with some turbulence on the surface of the strip. Said film should be maintained as far as the exit (2b) of the channel. To this end, additional jets (4) between the channel entrance (2a) and the channel exit (2b) are oriented in the opposite direction to the direction in which the strip is transported (5) and the pickling medium (3) is further delayed in flowing out at the channel exit (2b) by mechanical resistance devices (7) situated in the path of the transport channel (6).