Police said someone used a skill saw-type tool to cut into the rear wall of the market at 350 Rowland Blvd., Sgt. Eric Riddell said.
The wall leads to the manager's office, and the thief then cut into a safe and took an undetermined amount of cash, Riddell said.
The owner of the market discovered the burglary and reported it around 6:15 a.m. today. Investigators believe the crime occurred within an hour or two of when it was reported.
Anyone with information on the case is asked to call police at (415) 897-4361.