Abstract: The device comprises a support element (6) arranged in parallel with the free end of a cassette lid (1b) which is to be opened. The support element is driven by a lever gear (7, 8, 9, 33, 34, 35) and, guided on arms (2, 3), can be lifted and lowered. Spring-biased pressure bolts (19, 20) guided on the support element (6) serve to reduce the pressure exerted on the cassette locking mechanism (1c, 1d) during unlocking as well as to close the cassette 1. A mounting plate (23) on which an unlocking member (25, 36) and its driving rotary magnet (26) are arranged is spring-biased into contact with the pressure bolts (19, 20). Moreover, an opening element (15) with check arms (15a, 15b) associated with the cassette lid (1b) is also pivotably mounted on the support element (6) and can be brought into an operative position in response to the position of the unlocking member (25, 36) and the position of the support element (6) respectively.