PURPOSE: An impurity filtering device for a drain outlet is provided to simply remove impurities from a filtering unit and to extend the cleaning cycle of the impurities. CONSTITUTION: An impurity filtering device(100) for a drain outlet comprises a body unit(110) and a filtering unit(120). The body part has a shape corresponding to the inner shape of a drain outlet. The filtering unit has filter lattices(121). The filter lattices are extended in a direction crossing with the body part. The filter lattices have free ends(121a) separated from each other.
