▎ 摘　　要

NOVELTY - A microporous layer slurry comprises a gel formed by using a hydrophobic agent, a perfluorosulfonic acid type polymer or its corresponding salt, and solvent, and a carbon-based material dispersed in the gel. The mass ratio of carbon-based material and solvent is 1:(3-20). The mass of hydrophobic agent is 20-30% of the mass of the carbon-based material. The mass of perfluorosulfonic acid type polymer or its corresponding salt is 2-300% of the mass of the carbon-based material. USE - The microporous layer slurry is useful for preparing gas diffusion layer used in fuel cell (all claimed). ADVANTAGE - The microporous layer slurry forms gas diffusion layer having excellent gas transmission capabilities, and does not affect service life of product. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of the microporous layer slurry; and (2) preparation of gas diffusion layer, which involves covering the microporous layer slurry on a surface of base layer, and heat-treating.