To provide an information storage device and a control method therefor that enhance the security of stored data without lowering operability.

The information storage device has a readable/writable information storage means with a personal identification code registered, an input means into which an operator inputs a personal identification code, a reading means for reading out the personal identification code input from the input means when the information storage device is loaded into an electronic apparatus, and a determination means for determining whether or not the code input from the input means matches the personal identification code registered in the information storage device. While the information storage device is loaded in the electronic apparatus, if the code input from the input means matches the personal identification code registered in the information storage device, information stored in the information storage device is permitted to be read out by the electronic apparatus.