Runners in the mine. Photo: Jessica Gow/TT
"This is going to be a world-wide exclusive running experience that will take place up to 40 metres underground," Fredrik Trahn, the Sicklaloppet spokesman, said in a statement.
The event will be held in late September below the Atlas Copco headquarters in Sickla, southern Stockholm.
A practice run was held on Thursday on the 2.5 kilometre track with a handful of runners bearing hard hats.
The mines are usually used for test-drilling and product development.
The race will be held on September 21st, the same day as the traditional (and above ground) Sicklaloppet will be held.
There will be 400 places available for the run, but be quick, places go on sale on June 18th at 9am sharp. The money will be used to fund the company's charity project "Water For Everyone".
Stockholm-based Atlas Copco, which manufactures products ranging from mining drills to air compressors, has nearly 40,000 employees world-wide and an estimated market value of 217 billion kronor ($33 billion), according to the Bloomberg news agency.