Firefighters were called to the Tesco supermarket in London Road, Loudwater at 5.37pm on Tuesday 12th January 2016 after fire broke out.
The fire, believed to be an electrical fire started in the ceiling on the ground floor.
One fire appliance with crew attended from High Wycombe fire station as well as one from Beaconsfield fire station. An office also attended.
A thermal imaging camera and a tool kit were used by firefighters at the scene.