Silver nanoparticles (Ag NPs) as antibacterial agents are of considerable interest owing to their simplicity, high surface area to volume ratio, and efficient oligodynamic properties. Hence, we investigated the synthesis of silica-supported Ag NPs (SiO@Ag) as an effective antibacterial agent by using a wet-impregnation method. The formation of SiO@Ag with Ag NP (5-15 nm diameter) on the silica particle (100-130 nm diameter) was confirmed with transmission electron microscopy (TEM). The study on antibacterial activity was performed in a liquid culture to determine the minimum inhibitory concentration (MIC) against and bacteria. Both bacteria are chosen to understand difference in the effect of Ag NPs against Gram-negative and Gram-positive bacteria. SiO@Ag mesoporous nanoparticles had excellent antibacterial activity against bacteria and fully restricted the bacterial growth when the material concentration was increased up to 1.00 mg/mL. In addition, the obtained material had good adhesion to both steel and polyethylene substrates and exhibited a high inhibition effect against bacteria.