Known as the thermopolium, Latin for hot drinks counter, the store was discovered on the Regio V site of the archeological park, which is not yet open to the public, and was unveiled on Saturday.
Traces of nearly 2,000-year-old food have been found in some of the deep terracotta jars containing hot food that the store owner dropped into a counter with circular holes.
The front of the counter was decorated with brightly colored frescoes, some depicting animals that were part of the ingredients in the food sold, such as a chicken and two ducks hanging upside down.
“It is an extraordinary discovery. It is the first time we have excavated an entire thermopolium,” said Massimo Ossana, director of the Pompeii Archaeological Park.
Archaeologists have also found a decorated bronze bowl, known as patera, ceramic jars used for cooking stews and soups, wine balloons and amphorae.
Pompeii, 23 km (14 miles) southeast of Naples, was home to about 13,000 people when it was buried under ash, pumice and dust, as it withstood the force of an eruption equivalent to many atomic bombs.
“Our preliminary analysis shows that the figures drawn on the front of the counter represent, at least in part, the food and drink that were sold there,” said Valeria Amoretti, the site’s anthropologist.
Amoretti said traces of pork, fish, snails and beef were found in the containers, a discovery he called “a testament to the wide variety of animal products used to prepare the dishes.”
About two-thirds of the 66-hectare (165-acre) ancient city was discovered. The ruins were not discovered until the 16th century and organized excavations began around 1750.
A rare documentary of Greco-Roman life, Pompeii is one of the most popular attractions in Italy and a UNESCO World Heritage Site.