It happened on January 21 inside the restaurant located at 117 South 16th Street.
The suspect walked into the restaurant at 5:18 p.m. and placed an order.
He waited around until all customers left the store, then approached the counter.
VIDEO: Click here to watch the surveillance video
Hiding an unknown weapon under a newspaper, he demanded the clerk to fill a bag with money from the register.
The robber then fled the store north on Chestnut Street.
Police describe the suspect as a black male, 40-50 years old, 5'8" tall and 210 lbs. with a light complexion and freckles. He was wearing a tan/white hooded sweatshirt and blue jeans with an unknown weapon concealed with newspaper.
Anyone with information on these suspects should call police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).