Silica gel modified with a surfactant, Triton X-100 molecular assembly containing an extractant, 1-(2-pyridylazo)-2-naphthol, was prepared as an adsorbent to adsorb palladium, platinum, and gold. In this study, methods of metal recovery and mutual separation from the metal coexisting solution were studied by using the modified silica gel (PT100S). The effects of pH, chloride-ion, and metal-ion concentrations on the metal adsorption rate were evaluated through batch experiment. Pd(II) and Au(III) were adsorbed on PT100S, while Pt(IV) was not adsorbed. Furthermore, it was found that Pd(II) reacted with an adsorption site on PT100S, and that Au(III) reacted with a different adsorption site from Pd(II). These results enabled to separate the metals using a column packed with PT100S.