PURPOSE: To inject two kinds of fluid with one injection valve and by providing an additional needle valve which works with fuel oil from a first fuel passage and opens and closes a passage between a second fuel entrance and a second injection hole.

CONSTITUTION: A two-fuel injection valve has a first injection hole 1 which injects first fuel and a second injection hole 19 which injects second fuel. An additional needle valve 33 opens and a passage between a second fuel entrance 30 and the second injection hole 19. A first needle valve 2 is opened by fuel pressure of the first fuel, and the first fuel is injected from the first injection hole 1. After that, the additional needle valve 33 which opens and closes the passage between the second fuel entrance 30 and the second injection hole 19 by the fuel oil pressure from a first fuel passage so as to inject the second fuel from the second injection hole 19. Consequently, two kinds of fluid are injected with one injection valve.