This article reviews a model catalyst method, which has so far been used to investigate the size effects of ultrafine noble metal particles (Pt, Pd and Au) on fuel cell-related reactions, such as, the anodic oxidation of C₁ compounds including CH₃OH, HCHO, HCOOH and CO; the adsorption, absorption and desorption properties of hydrogen; the cathodic reduction of molecular oxygen. The particle electrodes are prepared by evaporating metals under vacuum on a flat dense substrate-glassy carbon, instead of porous substrates (e.g. active carbon, carbon black etc.). In addition, some mechanisms for these electrode reactions are also discussed. Moreover, further trials as the model catalyst method are also reviewed. Various techniques including CV, i-E, DEMS, XPS, UPS, HR-SEM, AFM, TEM and FT-IR etc. have been used.