The incident occurred on the 2000 block of North Gratz Street shortly after 7:30 p.m.
Police say at least one of two male suspects entered the store and announced a holdup.
During the attempted robbery, police say one of the suspects shot a 56-year-old man in the right shoulder.
The two men then fled from the scene.
The victim, an employee, was transported to Temple University Hospital in stable condition.
It is not known if the suspects left with any money.