In an air passage switching device using a film-type sliding door for an air-conditioning
unit for a vehicle. A grid member is provided in an air passage to extend parallel
with the sliding direction of a sliding door and divide an opening of the air passage
into a plurality of smaller openings. The sliding door has a film member, a door
plate supporting the film member, and elastic pressing means for pressing the film
member against edge seal faces of the air passage. A grill spacing between the
door plate and the end face of the grid member, is larger than an edge seal face
spacing between the door plate and the edge seal faces.
