The Thomas Organ Manufacture, located in Ster Francorchamps, currently employs 17 people and handles all stages of organ construction or restoration: keyboards, casings, sculptures, soundboards, bellows, mechanics, wooden and tin pipes, and harmonization. Over the course of 45 years, more than 130 new instruments have been crafted in these workshops. The company has also undertaken approximately 40 restorations of organs from the 18th and 19th centuries.

The organ of the Monaco Cathedral, whose restoration was entrusted to Dominique Thomas, was originally built in the 1970s by Jean-Loup Boisseau. It is a 5-manual instrument of excellent sound quality. During the restoration work, 60% of the existing pipes were preserved, but everything else is new.