The present invention provides a method for manufacturing a membrane-electrode assembly for a polymer electrolyte fuel cell, in which the glass transition temperature of an electrolyte membrane is reduced using a hydrophilic solvent, and a membrane-electrode assembly for a polymer electrolyte fuel cell, manufactured by the method. In the method of the invention, the glass transition temperature of the electrolyte membrane to which a catalyst is transferred is reduced compared to that in a conventional method for manufacturing a membrane-electrode assembly for a polymer electrolyte fuel cell using the decal process. Thus, even to an electrolyte membrane material having a relatively high glass transition temperature, the catalyst may be transferred at a rate of 100% at a temperature of about 120° C., at which hot pressing is carried out. Thus, the problems associated with electrolyte membrane deterioration occurring in conventional methods can be solved.