FUEL INJECTION VALVE

PROBLEM TO BE SOLVED: To inhibit variations of spray length of fuel spray, an injection direction and a state of atomization regarding injected fuel from a nozzle hole.SOLUTION: In a fuel injection valve, there are provided a valve seat 150 that forms a fuel passage 17 with a valve seat surface 151 reducing its diameter toward a fuel downstream side, and a sack portion 152 that forms a sack chamber 154 with a recessed portion 153 that opens toward a fuel upstream side, and allows an inner peripheral surface 155a of a nozzle hole 155 to intersect the surface 159 on a center axis line 18 side of an imaginary tapered surface 159 along the valve seat surface 151. The recessed portion 153 has a flat surface shaped bottom surface 156 that is opposed to flat tip end surface 42 of valve members 40 seating on the valve seat surface 151 spaced by a predetermined distance, and secures the sack chamber 154 with a size enough to inhibit the biting of mixed foreign substances between itself and the tip end surface 42, a nozzle hole opening surface 157 with the nozzle hole 155 opened, and formed in a tapered surface shape which reduces its diameter toward the bottom surface 156, and a connection surface 158 that is formed in a recessed curved shape recessed toward fuel downstream side of an imaginary tapered surface 159, and connects the valve seat surface 151 and the nozzle hole opening surface 157.