PURPOSE: To increase durability by preventing damage to a pilot valve of a fuel cut-off valve.

CONSTITUTION: A fuel cut-off valve 50 is provided in a pipe 27 through which high pressure compressed natural gas stored in a gas container is led, after decompression, to the intake system of an engine main body, and the fuel cut-off valve 50 is provided with a pilot valve 54 and a main valve 53 which open and close automatically by the energization and deenergization of a coil 62 when an engine is operated and stopped, respectively. Also the pilot valve 54 is provided with multiple small injection holes 52e interconnected to a gas downstream side inside a main valve body 53b and a pilot valve body 54b with small pressure receiving area on the gas upstream side which opens and closes the injection holes 2e by connecting it to the main valve body 53b so that it can be moved independently. Then a rubber sheet 54c is installed at the top of the pilot valve body 54b so that multiple injection holes 52e are opened and closed and, in addition, enclosed.