Passengers and crew vacated the Airbus A320 in an orderly fashion, it said, adding federal police had received the bomb threat.
A total of 132 people were aboard the plane, including 126 passengers and six crew members, Spiegel-Online reported.
An examination of the baggage and the aircraft itself yielded no results, Germanwings said in a separate statement later on Sunday evening.
Germanwings said passengers would be able to fly to Milan on a different aircraft on Sunday night while the searched plane has been cleared for air traffic.
Lufthansa has faced questions about its pilot screening process since the March 24 Germanwings crash which appears to have been caused by a co-pilot who suffered from depression and deliberately steered the plane into a mountain.