Firefighters have extinguished the blaze on the roof of the Blommer Chocolate Factory on the Near West Side, Fire Media said.
A cooling tower on the roof was burning, a fire department official said.
A still and box alarm was called about 1:50 p.m. in the 400 block of North Jefferson and the fire was put out about 2:45 p.m., according to Fire Media.
Fire and smoke were visible for some distance from the chocolate factory.
Fire officials are now using fans to pull smoke out, Fire Media said. An official address of fire will begin at 3:15 p.m. at 600 West Kinzie Street.
No injuries have been reported.