Two men – who donned black jackets with their hoods up – entered the shop armed with metal pipes.
One man was white and the other was black. Both were in their 20s and were average height.
They took a quantity of cash from the till before fleeing on foot.
Detective Sergeant John Seaton, from GMP’s Trafford borough, said:
“This was a brazen armed robbery where two men demanded money from terrified staff.
“Customers were also in the store at the time and were understandably scared by what they were witnessing. Thankfully no one was injured.
“We are trying to establish who these men are and we are following several lines of enquiry.
“I would appeal to anyone who was in the area at the time, or who might have information about this robbery, to please contact me.”
Information can be passed by calling Trafford CID on 0161 856 0945. Alternatively, information can be given anonymously to the independent charity Crimestoppers by calling 0800 555 111.