It happened around 10:30 a.m. at the BB&T Bank on 7800 Main Street.
Police say Scott Wessells, 25, of Ettawah Trail, walked into the bank and showed the teller a note indicating that he had a bomb.
Three bank employees and no customers were inside at the time of the robbery. Police say Wessells was able to escape with several thousand dollars.
Police say Wessells was arrested shortly after the robbery at a condo on Hailey Lane. Earlier in the day some of the money was recovered, however, police say at this point they're uncertain how much of the stolen money has been found.
The Middletown Police were assisted by the Frederick County Sheriff's Office, Strasburg Police, state police and the FBI.
Wessells is charged with armed robbery and is currently being held at the Shenandoah County Jail.