A fuel injection device configured to be supplied with fuel from a common rail, the fuel injection device comprising: a fuel injection valve for injecting fuel, which is distributed from the common rail; a pressure sensor located in a fuel passage, which extends from the common rail to a nozzle hole of the fuel injection valve, the pressure sensor being located closer to the nozzle hole than the common rail and configured to detect pressure of fuel; and a storage unit storing individual difference information, which indicates an injection characteristic of the fuel injection valve, the injection characteristic being obtained by an examination consisting in measuring the characteristics for each injector resulting from test-injection, wherein the individual difference information indicates a relationship between an injection state when the fuel injection valve performs fuel injection and a fluctuation in detected pressure of the pressure sensor, the fluctuation being attributed to the fuel injection, characterized in that the individual difference information indicates a relationship between an increase rate (Rα) of increase in an injection rate in an injection rate increase period and a decrease rate (Pα) of decrease in the detected pressure, or the individual difference information indicates a relationship between a decrease rate (Rλ) of decrease in an injection rate in an injection rate decrease period and an increase rate (Rλ) of increase in the detected pressure, wherein the injection rate increase period is in a time period from an actual injection start point, in which the actual injection start is started and which is subsequent to an output of an injection instruction (Is) to the fuel injection valve, to a maximum injection rate reach point, the decrease in detected pressure is attributed to the increase in injection rate, the injection rate decrease period is in a time period from an injection rate decrease start point to an actual injection end point, and the increase in detected pressure is attributed to the decrease in injection rate. a fuel injection valve for injecting fuel, which is distributed from the common rail; a pressure sensor located in a fuel passage, which extends from the common rail to a nozzle hole of the fuel injection valve, the pressure sensor being located closer to the nozzle hole than the common rail and configured to detect pressure of fuel; and a storage unit storing individual difference information, which indicates an injection characteristic of the fuel injection valve, the injection characteristic being obtained by an examination consisting in measuring the characteristics for each injector resulting from test-injection, wherein the individual difference information indicates a relationship between an injection state when the fuel injection valve performs fuel injection and a fluctuation in detected pressure of the pressure sensor, the fluctuation being attributed to the fuel injection, characterized in that the individual difference information indicates a relationship between an increase rate (Rα) of increase in an injection rate in an injection rate increase period and a decrease rate (Pα) of decrease in the detected pressure, or the individual difference information indicates a relationship between a decrease rate (Rλ) of decrease in an injection rate in an injection rate decrease period and an increase rate (Rλ) of increase in the detected pressure, wherein the injection rate increase period is in a time period from an actual injection start point, in which the actual injection start is started and which is subsequent to an output of an injection instruction (Is) to the fuel injection valve, to a maximum injection rate reach point, the decrease in detected pressure is attributed to the increase in injection rate, the injection rate decrease period is in a time period from an injection rate decrease start point to an actual injection end point, and the increase in detected pressure is attributed to the decrease in injection rate.