Firefighters and police were called to a blaze at the old scout hut on Duchess Street in Creswell last night (Tuesday).
Crews from Staveley, Bolsover and Clowne attended just before 10pm and found the hut well alight.
It took them just over half an hour to bring the blaze under control.
A Derbyshire Police spokesman confirmed that a joint investigation with the fire service is underway.
The fire is being treated as suspicious.