West Midlands Fire Service was called to Church Hill Street, Smethwick at 5.21pm on Monday to reports of a blaze.
The fire was described as 'out in the open' but affected the nearby Star Supermarket, and resulted in Church Hill Street being blocked off.
West Midlands Police also attended the scene to assist with closing the road.
A spokesperson for West Midlands Fire Service said: "We received the first call at 17.21pm. One crew is in attendance with a hydraulic platform.
"It is a large fire out in the open that has affected a supermarket which had to be evacuated.
"We are using HP to ensure no fire spread to the roof."
The road was open again by 9pm.