The fundamental investigation on extraction of Pd(II), Pt(IV), Cr(VI), Cu(II), Ni(II) and Zn(II) from an aqueous solution by using microcapsules containing a metal extractant was investigated. As extractants, 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) and tri-n-octylamine loaded with hydrochloric acid (TOA-HCl) were used. The extractants were successfully encapsulated in the microcapsules during the in situ microencapsulation process. The extractability of the metals into the microcapsules was estimated from the extraction isotherm of the metals. According to the Langmuir model, the saturation amount of metal extracted and the extraction equilibrium constant were determined. The microcapsules containing EHPNA and TOA-HCl were suitable for the extraction of base metals and precious metals, respectively. It is anticipated that a reactor in which two columns packed with each microcapsule containing EHPNA and TOA-HCl are connected in series would be useful for separation and recovery of precious metals from base metals.