NOVELTY - Producing hydrogen involves decomposing an organic substrate electrolytically in the presence of an enzyme catalyst to provide hydrogen.    USE - For producing hydrogen serve as fuel for the PEM fuel cell unit for generating electric power while the current control unit controls production of hydrogen to correspond to the load. The generated electric power is used for the electricity consumption of the electrolytic cell, or the part of the generated electric power is used for the electricity consumption of the electrolytic cell, the rest used for the electricity consumption of the application device (claimed); as a power source particularly for portable electronic devices, such as portable computers, mobile phones, iPod devices, and cameras with a required power of 0.1-20 W.    ADVANTAGE - The method allows hydrogen to be produced with less energy; can implemented by way of self-sufficient energy supply because the electric energy generated of the produced hydrogen with a fuel cell is greater than the electric energy consumed for producing hydrogen in electrolysis; enables a larger energy store to be carried with devices, compared with the use of accumulators and batteries; enables, with low manufacturing costs, production of an environmentally friendly, efficient and small-sized energy source which the end user will find easy to use and which can made disposable and destroyed in a safe manner without loading the environment.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) an electrolytic cell unit for producing hydrogen comprising an anode compartment (A) provided with an anode, a cathode compartment (B) provided with a cathode, and a proton exchange membrane (PEM) between them, where the anode compartment comprises organic substrate, enzyme catalyst and, optionally, mediator for transferring electrons to the anode, and the cathode compartment comprises water and metal or enzyme catalyst; and    (2) system comprising the electrolytic cell unit, a PEM fuel cell unit and an electronic current control unit.