Abstract: The invention relates to a cabin for carrying out treatments in it, comprising four walls which are arranged in pairs in spaced substantially parallel relation, the two pairs of walls being mutually substantially perpendicular and at least one or a part of one of the walls being constructed as a door for access to the cabin, and a roof connecting at its lower side as a ceiling onto the four walls and in which the roof comprises means for displacing streams of air in a substantially vertical direction from the ceiling through the cabin and at the bottom of the cabin means are provided for discharging air supplied from the ceiling, the roof comprising a more or less box-shaped construction, at least a part of a large area at the bottom of this construction forming the ceiling and said means comprising fans, valves, filters and air ducts mounted in the box-shaped construction of the roof, while a large portion of the ceiling is in the shape of a grid through which an air stream can be passed in a substantially d