The robbery happened at the William Hill shop on Maryhill Road. The suspect threatened staff with what appeared to be a firearm and demanded money.
Police said no firearm was discharged and no one injured but two staff members - a 20-year-old woman and a 21-year-old man - were "badly shaken".
The robbery happened at 6.40pm on Friday. The suspect is white, 5ft 11in and slim. He was wearing a black top with a white zip and black trousers. He had a black scarf on his face and was carrying a drawstring bag.