<p>The oil separator is disclosed, the oil separator according to the present invention comprises a baffle plate having an inlet port through which blow-by-gas containing oil is entered; a cylinder cover coupled with the baffle plate to form a chamber between the cylinder cover and the baffle plate, the cylinder cover having an outlet port through which blow-by-gas separated from oil is discharged; a hole-in-plate mounted on the baffle plate to divided the chamber into two independent chambers, the hole-in-plate having through holes formed one side thereof; and an impact member mounted on the baffle plate, the impact member being spaced apart from the hole-in-plate and an inner surface of the cylinder cover by a certain distance.</p>
