PURPOSE: To prevent breakdown of an IC with a built in memory cartridge which is due to an inadvertent operation by actuating an electronic circuit when the cartridge is put into a connector and stopping the actuation of the electronic circuit when the cartridge is pulled out of the connector.

CONSTITUTION: When a memory cartridge 1 is put into a connector 8, a projection 5 of a shutter 5 touches a catch lever of the connector 8 to open the shutter 5. Then a pin terminal 9 of the connector 8 touches a connection pattern of the cartridge 1 and then a contact is secured between a mechanical switch 10 set at the most inner position of the connector 8 and a case 2 of the cartridge 1. Thus a switch is pressed and a power supply is applied to the cartridge 1 to attain input/output of data. In addition, the breakdown of an IC incorporated to the cartridge 1 can be avoided by making use of combination between a magnet set at the end of the case 2 and the switch 10, and optical switch or a light source and a CCD sensor, etc.