A purification method excellent in removing particulates or the like from exhaust gas from an internal combustion engine, in particular, a diesel engine or the like. The purification method uses an exhaust gas purification apparatus including an oxidation zone installed with an oxidation catalyst supporting both platinum and palladium, and a filtering zone installed with a particulate filter, along exhaust gas flow at the exhaust gas passage of an internal combustion engine. Hydrocarbon-based liquid is supplied to the inflow side of the exhaust gas of the oxidation zone at the time when 2 to 10 g of particulates per 1 liter of the particulate filter are caught, to raise temperature of the exhaust gas up to equal to or higher than 550.degree. C. by the oxidation catalyst so as to make the residue of the particulate filter combusted.