The deadly incident occurred on Monday morning at a gun range in Arizona that caters to Las Vegas tourists, CNN reported.
Charles Vacca was accidentally shot in the head as he instructed the girl how to fire an Uzi, an Israeli-made 9 mm submachine gun.
As she pulled the trigger, the gun jumped out of her left hand toward Vacca, who was standing beside her.
He was airlifted to a hospital where he died from his injuries on Monday night.
No one was held guilty as the gun was licenced.
Gun experts on Wednesday said that young children should be taught to shoot with single-shot firearms rather than submachine guns.
They also said that safe learning is connected to the ability and experience of the instructor.