PURPOSE: To distinguish a cassette with an exposed film from a cassette with an unexposed film by providing two different areas constituted of two different colors.

CONSTITUTION: One color is given to one short side and one long side of the cassette, and another color is given to the other short side and the other long side of the cassette. In this case, the sides 14 and 16 are colored preferably red as shown by color dots in the figure, two of the other sides 18 and 20 are colored a different color, preferably black. By making a color code of the cassette in such a way, the cassette user can arrange the cassette with the exposed film and the cassette with the unexposed film in a prescribed direction so as to easily distinguish them. Besides, in the case of automatically loading the cassette to a multiloader and other devices, the cassette is easily loaded in a prescribed direction by a specified method.