Object of the present invention is to provide a dust collecting device (100) for a vacuum cleaner of which dust collecting performance is improved. For this, the dust collecting of the present invention includes two parallel primary cyclones (210, 220) for separating dust by a cyclone principle, and two secondary cyclones (250, 260) for separating dust introduced thereto from the primary cyclones (210, 220) by the cyclone principle, and a dust container (110) for storing dust separated by the primary cyclones (210, 220) and the secondary cyclones (250, 260), wherein the two primary cyclones (210, 220) surround the two secondary cyclones (250, 260), respectively.