A burglar with an appetite for fried food and fast cash has robbed a fish and chip shop in Melbourne's inner north.

Police say the man placed an order at the Lygon Street store in Carlton about 12.50pm on Wednesday, before asking staff where the closest toilet was.

The man then entered the store's upstairs office via the rear entrance, where he stole a large amount of cash from an unlocked safe.

“After the offender stole the cash ... he went downstairs, collected his order and left,” Detective Senior Constable Brooke Manley said.

Police believe the man was also behind an attempted burglary at a yoghurt shop on Faraday Street, Carlton, about 4pm on May 30.

The man is described as Caucasian, aged in his late 20s or early 30s, about 185 centimetres tall, with dark hair and a medium build.

Police have asked anyone with information to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppers.com.au.