A monopolar membrane electrode assembly (MEA) for a fuel cell, for example, includes: an electrolyte membrane; anode and cathode electrodes formed on opposite surfaces of the electrolyte membrane, respectively; current collecting bodies that form electrical paths of electricity generated from an electricity generation reaction between the anode and cathode electrodes and the electrolyte membrane; and sensing elements to measure changes in operation state conditions during electricity generation and electrical connection. Since temperature and fuel concentration in the monopolar MEA having the above structure are detected on a real time basis, appropriate action can be taken whenever an abnormal operation thereof is detected.