Abstract Silver (Ag) nanocatalyst has been deposited on SiO2 glass substrate by the thermal evaporation method. The layer thickness was about 2.42 mm. The Ag nanocatalyst was then annealed at a temperature of 400 °C with the variation of annealing time for 1, 2, 3, and 4 h. Several spectroscopy methods were carried out to characterize the samples. From the scanning electron microscope (SEM) images showed that the diameter size of the nanoparticles were mostly 0.252 μ m, 0.236 μ m, 0.193 μ m, and 0.108 μ m, respectively. Energy Dispersive X-ray (EDX) spectroscopy revealed that composition of Ag for each sample are 0.26%, 0.14%, 0.48% and 0.04% respectively. Based on the SEM, the smallest diameter of particles was obtained after annealing for 4 h, and EDX results, the most Ag composition was obtained after annealing for 3 h. The results from Fourier transform infrared (FTIR) spectroscopy do not indicate the presence of Si O Ag bonds at SiO2/Ag, where based on literature, their peaks are at 827 cm−1 and 1749 cm−1.