PURPOSE: To handle cassettes of different sizes by providing a crane with a chuck arm having a plurality of engaging sections shifted in the vertical direction.

CONSTITUTION: Guides 12 and 13 respectively for 8 and 6 inch cassettes corresponding to the legs 31 and 41 respectively for 8 and 6 inch cassettes are arranged in the mounting section 11 of a storage shelf 1, positioning each cassette. A crane 2 comprises a mast 21, lift table 22, turntable 2, and slider 24 and is provided with chuck arms 25 and 25 in approaching and separating relationship between them. The chuck arms 25 and 25 have a U-shape, and the top faces 251 and bottom faces 252 of the chuck arms are engaged with the fringe 32 of the 8 inch cassette 3 and the fringe 42 of the 6 inch cassette 4 respectively. This constitution makes it possible to handle cassettes of different sizes and to apply to a line wherein cassettes of different sizes intermixedly flow.