To provide a technique that fully reflects variations of injection characteristics of an injector for controlling the injector.

A battery system 10 is equipped with: an injector 314 that injects fuel gas flowing from a fuel gas supply source 302 toward a fuel battery 20; a pressure rising instruction part 914 that boosting anode pressure Pf by instructing the injector 314 to continuously inject while power generation by the fuel battery is being stopped; a correction calculation part 916 that calculates a correction value Rm to correct a reference characteristics value Fs of the injector 314 based on pressure variations Pf of the anode pressure by the instruction of the pressure rising instruction part and a learning injection time TL of the injector 314.