The present invention relates to a method for controlling a laundry treating apparatus including a drum for holding laundry, a connection duct for exhausting air from an inside of the drum, an exhaust duct provided parallel to a length direction of the drum connected to the connection duct, a filter assembly with a filter unit provided to the exhaust duct for filtering the air and a brush for removing foreign matter from the filter unit, a brush drive unit for making the brush to reciprocate a section of the filter unit, and a position sensing unit for sensing a position of the brush.