It happened at the store on the 4700 block of North Broad Street on December 26.
The suspect can be seen on surveillance entering the store around 8 a.m. and demanding money from the clerk.
The employee then removed the cash register drawer and handed it to the thief.
He got away with an unknown amount of cash before fleeing north on Broad Street.
Polcie describe the suspect as a black male, 5'7"-5'9" tall with a thin build, light complexion and stubbled beard. He was wearing a blue hooded sweatshirt and dakr blue "Dickie" pants.
Anyone with information should call police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).
VIDEO: Click here to watch the surveillance