Queensland police are looking for a robber who fired a gun at a local resident who tried to stop him fleeing a crime scene by hurling a piece of timber.

A gunman fleeing a shop he had just raided in north Brisbane fired at a man who tried to stop him.

Police say the robber, armed with a rifle walked, into a takeaway shop on Cresthaven Drive, Morayfield, about 4.45pm (AEST) on Thursday.

A female employee handed over some money from the till and the man then ran off.

A nearby resident saw the robber fleeing and threw a piece of timber at him, but missed.

The robber then turned and fired his rifle at the resident, also missing.

No one was injured.

Police are looking for the robber, who is described as being Caucasian in appearance, aged in his early 20s with a slim build.

He was seen driving away in a small, dark-blue hatchback.