A sectional door for controlling the access opening to a compartment, includes a fixed portion including two pairs of vertical guides extending in a direction substantially parallel to a respective shoulder of the opening; and a movable portion including a leaf having a lower panel and an upper surrounding panel, extending over the entire width of the leaf and having its lateral sides in sliding engagement along a respective side guide, a pair of side support arms each having one end thereof articulated in correspondence to the top of a respective pair of vertical guides and the other end thereof pivoted in correspondence to an intermediate zone of a respective lateral side of the upper panel, and articulated and slidable connection elements between the lower panel and the upper panel, whereby the lower and upper panels are movable between a closed, and an open position.