We irradiated a glassy carbon electrode in AgNO3 solution using a 532 nm pulsed laser to prepare a silver-activated electrode. The UV-visible spectrum of the solution evidenced the production of Ag particles, and transmission electron microscopic images showed the formation of carbon silver composite on the solid carbon surface. The reduction potential of O-2 measured with the prepared electrode by differential pulse voltammetry shifted positively by 0.05 V in NaClO4 solution, which indicated that the present irradiation procedure effectively activated the glassy carbon electrode.