Filter for cyclonic dust collection unit, cyclonic dust collection unit and vacuum cleaner with the same

Provided is a cyclonic dust collection unit (400) for conveniently removing a foreign object filtered therein. The cyclonic dust collection unit includes: a first filtering chamber (423) for filtering a first foreign object having a first size using a cyclone airflow; a second filtering chamber (424) for filtering a second foreign object having a second size smaller than the first size of the first foreign object, the second foreign object being contained in the air passed through the first filtering chamber; a foreign object storing chamber (416) for storing the first and/or second foreign object(s) separated through the first and second filtering chambers; a filter (405) disposed in the first filtering chamber, for separating the first foreign object on an outer surface thereof; and a cutaway hole (470) formed in a longitudinal direction thereof.