The robbery happened at 7:49 p.m. Tuesday at the Morel Food Market at 401 North 54th Street.
In surveillance video released by police on Friday morning, the suspect is seen entering the store, walking up to the counter and pulling a gun.
The man demanded money from the cash register, police said. After obtaining an undisclosed amount of money, the suspect fled east on Parrish Street toward 53rd Street.
The suspect is described by police as a black male, 20-30 years-of-age with a dark complexion. He stands 5'6" to 5'7" tall with a thin build wearing a black and orange baseball hat, dark colored t-shirt with "Made in Philadelphia" written on the front, dark colored "Nike" pants with a white stripe on the side. Police say he also has a tattoo of what appeared to be a sword or knife on the left forearm.
Anyone with information is asked to contact Philadelphia Police at 215.686.TIPS (8477), text a tip to PPD TIP (773847) or through phillypolice.com.