Abstract: A cassette changing device for a microtome has a housing having a loading opening, a transfer opening and an unloading opening. The openings are arranged with respect to each other linearly in the housing. A slide is disposed in the housing linearly movably between a first position and a second position and has a first receiving compartment and a second receiving compartment. The first and second compartments are aligned with respect to each other so that, in the first position of the slide, the first compartment and the second compartment are respectively aligned with a first two of the openings and, in the second position of the slide, the first compartment and the second compartment are respectively aligned with a second two of the openings.