Abstract: The invention is a device and a method for combining at least two fluid media. The device comprises a flow region (1) which is attached to and/or formed with an opening of a first chamber (2) and which is designed to accommodate the fluid medium coming from the first chamber and to transport it to the outlet (3) of the flow region (1) which is preferably followed by a mixing zone. A second chamber (9) designed to be filled with a second fluid medium is connected to the flow region and/or to the first chamber through at least one first opening element (inlet opening) (11) for diverting part of the first fluid medium from the first into the second chamber. The second chamber is provided with at least one second opening element (second opening) (12) opening into or adjoining the flow region (1) for discharging the second fluid medium displaced into it by the first fluid medium. Several first chambers (2) or second chambers (9) may be provided.