The present invention relates to a membrane electrode assembly for electrochemical cells, and a manufacturing method thereof. In the membrane electrode assembly, electro-catalytic layers forming electrodes on both surfaces of an ion-exchange membrane have a plurality of pores evenly distributed therein. According to the invention, the electro-catalytic layers are made porous, and thus the amount of precious metal used can be reduced so that the manufacturing cost of the catalytic layers can be greatly reduced. In addition, the reaction efficiency of the catalytic layers can be stabilized to improve the efficiency thereof.