Power tools were stolen when thieves targeted a number of industrial units at businesses in Station Road in Ilkeston.
Seven units either had their shutters forced open, doors damaged or windows smashed by offenders who got into them and made searches.
Burglars broke into the site during an estimated hour-long spree between 11.15pm on Wednesday September 3 and 12.15am the following day.
A spokesman for Derbyshire Police said calls were made to 999 when an alarm sounded from one of the units.
Officers have been compiling lists of the items that were taken, with power tools being the main target of the raid.
The break-in happened at units in Station Road.
Anyone who saw suspicious activity in the area at the time or has been offered good quality power tools at cheap prices is asked to contact Derbyshire Police on 101.