Firefighters were called to Totnes Road, Tweenaway, Paignton yesterday morning after a report of a fire in a supermarket.
Fire control had received a call from the duty manager of the supermarket saying she had discovered a room filled with smoke to the rear of the building.
Two appliances from Paignton were mobilised.
Fire crews found there had been a small fire in a food preparation area involving a pizza sealing machine.
The fire was out on arrival, and crews inspected the area to ensure it was safe.
The cause was accidental.