PURPOSE: To easily inject fuel of many kinds into a combustion chamber with a single of pump, in a fuel injection vlave injecting fuel of many kinds, by operating a piston valve, sucking fuel of different kind into a needle valve chamber, mixing the fuel and injecting this fuel into the combustion chamber.

CONSTITUTION: Working oil is fed to an inlet pipe 12, if applied to a piston valve 10, pressure in needle valve chambers 13a, 13b and fuel oil passages 105, 205 rises, and fuel is injected from an injection port 14 by opening a needle valve 1. Then pressure of a working oil feed pump is decreased, if the piston valve 10 is pushed back by a spring 9, pressure in the fuel oil passages 105, 205 is decreased lower than pressure in fuel oil inlet pipes 101, 201. If the pressure is decreased to a prescribed value, check valves 103, 203 are opened, and fuel oil of different kind in the fuel oil inlet pipes 101, 201 flows into the needle valve chambers 13b, 13a, then the fuel is mixed, in this way, this mixed fuel can be injected in the next step into a combustion chamber from the injection port 14 when the needle valve 1 is opened similarly as described in the above.