The multi-cyclone dust separating apparatus includes a first cyclone unit having a body and including an air inlet disposed at a side of the body, a first cyclone chamber adapted to form a first space for whirling air from the air inlet to separate dust form the air; a second cyclone unit adapted to be detachably disposed at the body of the first cyclone unit and including, a second air inlet to draw the air from the first cyclone chamber, at least one cyclone for whirling the air from the first cyclone chamber to provide a second separation of dust from the air; and a dust bin adapted to be detachably mounted to at least one of the second cyclone unit and the first cyclone unit.