The present study was directed towards investigating the relationship between the acid absorption of the catalyst layer and electrode performance and discussing the pores available for the cathode and anode reactions. The catalyst layer was formed on a porous carbon substrate by spreading a slurry consisting of a carbon‐supported platinum catalyst and PTFE dispersion. The nonionic surfactant contained in the dispersion enhances the acid absorption. Pores from 0.2 to 10 μm in diameter are available for the reactions.