The problem addressed by the invention is that of creating a sight glass device, in particular to permit optical and/or visual access to a closed chamber. This problem is solved in that the sight glass device comprises the following: a viewing shaft, which preferably adjoins the chamber, projects into the chamber, and/or is or can be fixed to the chamber; and a transparent glass element, which is arranged at an end of the viewing shaft that faces away from an interior of the chamber.
