PURPOSE: To reduce the number of terminals by one and to reduce the size of a device, by inputting a cassette ejecting signal to the same terminal of a microcomputer with a detection signal indicating the fact that a cassette is inserted up to a specific position of a holder.

CONSTITUTION: The microcomputer 5 is provided with terminals 10-10 other than a terminal for ejection, and the common terminal 9 for an ejection switch 7 and a cassette detection switch 6 for detecting whether a cassette is inserted up to the specific position in the holder is provided. When the ejection switch 7 is turned on, an L-level signal is inputted to the terminal 9 and the microcomputer 5 controls the running of a magnetic tape and ejects the cassette. On the other hand, if the cassette is not inserted enough while the ejection switch 7 is off, the switch 6 is still on and the L-level signal is inputted to the terminal 9 to perform the ejection as mentioned above, but once the cassette is inserted up to the specific position, the switch 6 is turned off and an H-level signal is inputted to the terminal 9 to run the tape. Thus, the number of terminals is decreased.