Object of the present invention is to provide a dust collecting device (10) for a vacuum cleaner of the dust collecting performance is improved. For this, a dust collecting device (100) for a vacuum cleaner is provided, including a primary cyclone unit (200) for separating dust by a cyclone principle, a secondary cyclone unit (300) around the primary cyclone unit (200) for separating dust from air discharged from the primary cyclone unit (200) by the cyclone principle, a primary dust container (111) for storing the dust separated at the primary cyclone unit (200), and a secondary dust container (112) in the primary dust container (111) for storing the dust separated at the secondary cyclone unit (300).