Fuel injection device

A fuel injection device comprising:

• a valve body which defines an injection port, a control chamber filled with a fuel, an inlet passage for introducing the fuel into the control chamber, and an inlet passage for discharging the fuel from the control chamber;
• a needle which will be displaced by a variation in fuel pressure in the control chamber so as to open/close the injection port;
• a closing member which is accommodated in the control chamber in a displaceable manner so as to close an inlet opening of the inlet passage, which opens on an opening wall confronting the control chamber;
• and
• a biasing member which is accommodated in the control chamber in such a manner as to bias the closing member toward the opening wall, wherein
• the control chamber is defined by a defining wall which has a dividing wall portion,
• the dividing wall portion divides the control chamber into a backpressure chamber for applying a fuel pressure to the needle and an accommodation chamber accommodating the closing member and the biasing member,
• the dividing wall portion has a restriction hole fluidly connecting the accommodation chamber and the backpressure chamber with each other, and
• the dividing wall portion has a support surface supporting the biasing member.