It happened around 7:00 p.m. Tuesday along the 1400 block of South 6th Street.
Authorities say three men walked into the store and announced a robbery.
No one was injured during the incident.
It's not clear if the men got away with anything but they fled the scene on foot.
Officers caught one of the suspects near 4th and Greenwich streets. They also were able to recover a gun.
Police took one suspect into custody and are looking for the remaining two.
Anyone with information is urged to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.