Mobile phones, laptops, smart watches and tablets are among the £35,000 worth of goods stolen from the Currys store in Gallagher Retail Park, Caerphilly.
Five unknown burglars removed part of the brick wall at the back of the store to gain entry.
The break-in is believed to have happened between 8pm on Wednesday, January 30 and 6.50am on Thursday, January 31.
The burglars also caused damage inside the store.
PC Stuart Lewis of Gwent Police said: “We are now investigating the burglary and are appealing for information from anyone who may have any information about the incident or those involved.
“We are also reminding those tempted into purchasing stolen goods at a reduced price are breaking the law. If you are knowingly buying stolen items, you are committing an offence of handling stolen goods.”
Anyone with information is urged to contact Gwent Police on 101, quoting log number 45 31/01/19, or through their Facebook or Twitter accounts.
Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.