Abstract: A hood for a wire part and/or a press section in a paper/board machine including walls and a ceiling which form a closed hood around the wire part and/or press section, air-conditioning or another air-control system being arranged in connection with the hood. The hood walls have outer and inner walls which define an air duct therebetween for passing a replacement air flow into the interior of the hood, preferably toward a middle area of the paper machine, through openings in the inner wall, the replacement air keeping the interior of the hood substantially dry and clean. The walls of the hood include a vertical side wall at the driving side, which wall is preferably fixed, and a tending-side vertical side wall and a ceiling formed as a single wall which is preferably L-shaped and displaceable. The displaceable hood wall at the tending side has two parts so that the first hood wall is placed by the wire section and the second hood wall is placed by the press section.