To provide a variable spray angle/injection hole type fuel injection nozzle applied to a pressure accumulation type fuel injection system and enabling multiple stage injection with making spray angle and injection hole section area variable or selective suitably to an operation condition of an internal combustion engine.

This fuel injection nozzle is applied to the pressure accumulation type fuel injection system, and is provided with acute spray angle/small diameter injection holes 48 bored on concentric circles and having spray angles and injection hole section area on same circumference unified, a nozzle body provided with a valve seat 52, a needle valve and a cylindrical needle valve seated on the valve seat 52 at an upstream of the acute spray angle/large diameter injection holes 49, a two way valve 47 capable of reciprocating slide driven by a piezoelectric actuator for controlling back pressure of the two kinds of needle valves, and a low pressure valve 36. Fuel is injected from the injection holes by separating the needle valve selected out of the two kinds of needle valves from the valve seat 52 by pressure difference of fuel existing in a first fuel reservoir chamber, a second fuel reservoir chamber, and a first low pressure chamber 34 respectively.