The present invention relates to a portable fuel cell apparatus, comprising: a fuel cell, an interface controller, a voltage regulating circuit and a memory unit, wherein the voltage regulating circuit comprises a circuit for converting the electric power into a steady voltage output, and the interface controller comprises a data communication transformation interface. The power is generated by the fuel cell and transmitted to the voltage regulating circuit to be converted into the steady voltage for being transmitted to the interface controller. The interface controller can perform the transmission and distribution of the electric power and the data access of the memory unit. In addition, according to the current output of the fuel cell, the power property thereof and the voltage demand of interface controller, the voltage regulating circuit converts the power from the fuel cell into the steady voltage to be transmitted to the interface controller 2 by means of buck logic and boost logic.