PRODUCTION METHOD OF POROUS LAYER MATERIAL AND PRODUCTION METHOD OF MEMBRANE ELECTRODE AND GAS DIFFUSION LAYER ASSEMBLY INCLUDING POROUS LAYER MATERIAL

A production method of a porous layer material for forming a porous layer includes the steps of obtaining particles that contain carbon and a water-repellent resin by spray drying a mixed solution that includes the carbon and the water-repellent resin, producing a paste that includes the particles, and extruding or rolling the paste to obtain the porous layer material in a sheet-like form.