The gaseous fluid stream treatment unit for treating a meat product cut into slices includes an enclosure (7) in which there is a conveyor device (1) with two or more vertical translation sections (9, 10) moving the trays (2) loaded with slices of the meat product in alternating opposite vertical directions, and at least one horizontal translation section (11) transferring the trays (2) from a final end of one of the vertical translation sections (9,10) to an initial end of the next vertical translation section (9,10). A gaseous fluid circulation device (8) generates a gaseous fluid stream inside the enclosure (7) in a substantially horizontal direction from a gaseous fluid inlet (12) to a gaseous fluid outlet (13) consecutively traversing the two or more vertical translation sections (9, 10) of the conveyor device (1), subjecting the slices to the action of the gaseous fluid stream.