Abstract: A mask loading apparatus and method employing a cassette (200) detachably mounted on an in-out cassette holder (212). The cassette is made of low Z-materials, and comprises a cover (211) and a bottom mask-supporting tray (202) locked by machine-operable locking members (224) to the cover. A lift cylinder (218) has a vacuum cup (216) which is raised to support and hold the underside (213) of the tray and, when the tray is unlocked from the cover, to move the vacuum cup, tray and mask downwardly and then laterally by a transport arm (203) to a fixed location under a mask holder (205, 220) in a lithographic apparatus.The lift cylinder then raises the cup, tray and mask to abut the mask holder and to transfer the mask to the mask holder. The lift cylinder and empty tray is then lowered and removed from a position blocking the mask as it is to be used in the lithography processing. A reversal of the sequence of steps is utilized to unload the mask from its use mode and return it to its cassette cover.