this invention relates to a pleated high efficiency particulate air filter and separators therefor in which the separators comprise a lattice with flat or rounded spacers , a rounded pleat fold contacting member , and vertically spaced apart air inlet and outlet media supporting flat members to provide uniform internal support for the pleats , and to eliminate sharp edges and corners which would tend to injure the media under compression . the separators may be formed of plastic by molding into a single unit or into multiple segments which may be joined side by side to provide a desired separator length . the structure permits enclosure and bonding of the assembled pleats and separators with the end portions of each encased by a bonding material .