PURPOSE: To eliminate the need of care for whether or not a cassette is mis- loaded, by providing a mis-loading detecting means of a magnetic disc cassette to a device side so as to eject automatically the cassette when the mis-loading is detected.

CONSTITUTION: When a magnetic disc cassette 5 is loaded in the correct direction, a timer signal for mis-loading detection rises to a high level in synchronizing with the rise of a magnetic disc clamp signal and goes to a low level after a prescribed time. On the other hand, if a ready signal is not at high level when the mis-loading detecting timer signal falls down to a low level, the magnetic disc device is discriminated that a disc cassette 5 is mis-loaded. In this case, a drive signal of a motor goes to high level and a forward/reverse signal of the motor is confirmed to the low level. As a result, the mis-loaded magnetic disc cassette 5 is ejected automatically from a loading port 4 to the outside of the device with a drive roll 7.