To improve information leakage prevention performance by preventing a user of a terminal or the terminal itself from going to the outside of the space when an important file is stored in the terminal.

The terminal 4 is provided with a download information transmitting means 42 for transmitting download information including peculiar information 10 and file identification information 32 of a downloaded file to a gate control part 5 when a file 31 from a file server 3 is stored in a terminal side storage means 41; and the gate control part 5 is provided with a propriety determination means 500 for outputting determination result of whether passing is proper or improper in accordance with importance of the file 31 related to the download information, a determination result storage means 510 for storing the determination result in association with the peculiar information, and a gate operation control means 520 for making a gate 2 to perform obstructing operation when the determination result of the determination result storage means 510 in correspondence with the read peculiar information 10 is that the passing is improper.