An apparatus for testing the airtightness of a separator for a fuel cell includes: a jig unit being in close contact with a surface of the separator on which an airtightness line is formed, and having a test flow field formed thereon, the test flow field being opened to a location contacting the airtightness line of the separator; and a test solution supply means for supplying a test solution to a contact location at which the airtightness line of the separator and the jig unit contact to each other through the test flow field of the jig unit, such that a leakage of the test solution at the contact location is tested.