It happened around 8:00 Wedensday night at the store at 11 Red Mill Road.
Police say the suspect grabbed the clerk, pulled out a large handgun and demanded money from the register. He then fled on foot with an unknown amount of cash.
The suspect is described as a black man in his mid 30's to late 40's with a dark complexion, goatee or full beard. He was about 6'2" to 6'4" tall, approximately 250 lbs., with a large build.
He was wearing a plain black hooded sweatshirt with the hood up, black belt, blue jeans and tan boots.
The suspect did not wear any gloves.
Anyone who may know the suspect is asked to call 302-834-2630 ext. 6 or Crime Stoppers at 1-800-TIP-3333.