A dust separating apparatus is provided to improve dust collecting efficiency, by compactly forming a filter unit of a grill filter for filtering large dust and a porous filter for filtering fine dust. A cyclone body(20) separates dust from air using a centrifugal force. The cyclone body has an input pipe(26) into which the air is putted. A dust collecting can(90) is detachably joined to a bottom end of the cyclone body. The dust collecting can collects the dust separated from the air. A filter unit(40) is detachably joined to the cyclone body. The filter unit is compactly formed in a double structure of a first filter for filtering large dust and a second filter for filtering fine dust.
