Flames were spotted in a building housing the store on the Grand Rue at around 3.40pm, Fribourg cantonal police said.
The fire started on the ground floor and spread elsewhere, police said in a statement.
The upper floors as well as the facade of the building were seriously damaged, the statement said.
City fire fighters were able to quickly bring the blaze under control and no-one was injured.
As a precaution occupants of an adjacent building were evacuated but it escaped damage, police said.
A section of the street was closed while emergency services workers responded to the scene.
Local newspaper La Liberté said the building was empty at the time.
The newspaper reported a neighbour said a candle was responsible for setting the structure on fire.