An American gun safety instructor has accidentally shot a student during class at a training facility in Ohio.

Terry Dunlap was showing a handgun to the 29 students attending a concealed-carry class at his shooting range near the city of Lancaster when the weapon went off.

The 38-calibre bullet ricocheted off a desk and hit Michael Piemonte, 26, in the upper arm.

"Everyone was in shock," Piemonte said. "It took me a couple of seconds to realise I had been shot."

After first aid by nurses who were also attending the course, Piemonte was taken to a hospital and released a few hours later.

He had been attending the course with his wife Alison.

"My wife was sitting just inches away from me. It could have easily hit her," he told the Columbus Dispatch.

He said that Dunlap did not seem to realise that the gun was loaded.

"I am thankful that it only ended up being in my arm, and didn't hit my wife or individuals sitting at the desk behind me."

The couple were planning to buy a gun and under state laws gun safety classes are compulsory for first-time buyers.

Police listed the incident as accidental and no charges have been filed.

"It was the first time I've been shot, and hopefully the last." Piemonte said.