NOVELTY - The method involves sticking and conveying polymer electrolyte membrane, first gas diffusion electrode and/or second gas diffusion electrode to adhesive sheet (100). The adhesive force of adhesive sheet is lowered and adhesive sheet is peeled by external stimulation by giving external stimulation to adhesive sheet. The first gas diffusion electrode and second adhesive sheet are laminated on surface on opposite side to first adhesive sheet of polymer electrolyte membrane.    USE - Manufacturing method of fuel cell membrane/electrode composite structure.    ADVANTAGE - The assembly of elements are efficiently performed by conveying polymer electrolyte membrane, gas diffusion electrode, or gas diffusion layer, such that the decline in adhesive force is reduced effectively. The deformation of polymer electrolyte membrane and occurrence of wrinkles are prevented reliably. The production efficiency of fuel cell membrane/electrode composite structure is improved reliably.    DETAILED DESCRIPTION - The second gas diffusion electrode and third adhesive sheet are laminated on surface on opposite side to gas diffusion electrode of polymer electrolyte membrane. The responsiveness with respect to external stimulation of first adhesive sheet is differs from responsiveness with respect to external stimulation of second adhesive sheet. The adhesive sheet is equipped with adhesive layer that contains thermally expansible microsphere. The heat is used as external stimulation for lowering adhesive force of external stimulation for lowering adhesive force of first adhesive sheet and lowering adhesive force of second adhesive sheet and third adhesive sheet. The relationship between temperatures of external stimulation for lowering adhesive force of multiple adhesive sheets has predetermined relation. The circumference of the first gas diffusion electrode is enclosed. The first gasket is stuck and conveyed to second adhesive sheet with first gas diffusion electrode, when conveying first gas diffusion electrode.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic sectional view illustrating the manufacturing method of adhesive sheet.    Adhesive sheet (100)    Base material (110)    Adhesive layer (120)