Police reported that the masked robber entered the petrol station at around 9.25am last Sunday. Immediately he pulled out an enormous sword in front of the cashier and demanded money from the till.
The 35-year-old employee at first didn't react, but then the sword-wielding man physically threatened him with the weapon, forcing the shop worker to open the till.
The thief took the cash inside before fleeing. The cashier was unharmed.
Police on Wednesday released CCTV footage of the robbery to help them search for the culprit.
The suspect is described as being between 30 and 40 years old, about 1.7 metres tall, with dark hair and a fair complexion. He is seen in the video wearing a camouflage jacket and jeans, and also carrying a distinctive red box.