An electrochemical hydrogen flow rate control system is provided. The system has an electrochemical cell and a hydrogen flow rate control unit. The electrochemical cell includes a first electrode for generating protons (H⁺), a second electrode for converting the protons generated by said first electrode into hydrogen gas, and a proton conductive solid electrolyte membrane held between said first and second electrodes. The hydrogen flow rate control unit is adapted to generate a specific amount of hydrogen gas on the second electrode side. The proton conductive solid electrolyte membrane is made from a fullerene derivative obtained by introducing proton dissociative groups in carbon atoms of fullerene molecules. Such a control system is operable even in a non-humidified atmosphere and at room temperature and is configurable as lightweight and compact in system design.