The gang of five men - armed with what is believed to be a baton - targeted an Asda store in Cannock on Tuesday.
Staff at the Surrey Close store were threatened before they were forced to hand over cash from tills.
Police were called to the store at 10.10pm after the perpetrators fled in a vehicle.
A Staffordshire Police spokeswoman said: "Nobody was seriously hurt during the robbery but the staff were understandably left shaken and upset."
Witnesses with CCTV or dash cam footage which could help the investigation are now being urged to get in touch with police.
Call 101, quoting incident number 951 of November 6.