Two masked men entered the One Stop Shop, in Barkham Ride, shortly before 10pm on Saturday and attempted to break into a cash machine. The men, who were armed with what officers believe were bats or lengths of wood, fled after failing to access the cash inside the machine.
The would-be robbers left in a Red Toyota Corolla GT with square rear and front number plates, which police believe was driven by a third accomplice. When driving away from the store, the car turned left onto Barkham Ride heading towards Finchampstead.
One of the men is described as wearing a green hooded top with white cords and a large white motif on the front, with large white letters along the top. He was also wearing grey jogging bottoms and black trainers.
The second man was wearing a grey hooded top with white cords and a zip. He was wearing a white t-shirt under the top, dark blue jogging bottoms and dark trainers with a white line along the sole.
Witnesses should call the police on 101 or Crimestoppers on 0800 555 111