An electrode for a fuel cell, and a membrane-electrode assembly and a fuel cell system that include the electrode are disclosed. An electrode for a fuel cell that includes an electrode substrate, a first channel formed in the electrode substrate, a first hydrophilic interface formed on an inner surface on one side of the first channel which guides liquids, and a first hydrophobic interface formed facing the first hydrophilic interface which guides gases, makes it possible for water obtained as a side product at the cathode to be separated from air without additional devices, so that it has a potential for utilization not only in portable electronic devices but also in low-capacity power source devices.