To provide an atmosphere-controlled experimental heating device of which the structure is simplified, the installation of which is facilitated and which is used conveniently at a laboratory as a practical instrument by a user conducting an experiment, particularly an electrochemical experiment, in an atmosphere of reactive gas at high temperature.

This atmosphere-controlled heating device is composed of: a chamber (C) consisting of a glass tube (1), heat-resistant resin-made upper and lower annular flanges (2a), (2b), a top cover (3) and a brass flange (5); and a heating part (H) consisting of an infrared radiation unit (21), a halogen lamp (23) and a mirror (22). A high temperature region is formed in the inside of the chamber (C) in such a condition that the heating element of the heating part (H) is completely isolated from the high temperature region in the chamber (C) by arranging the heating element on the outside of the chamber (C) and the high temperature region of the chamber (C) in the inside.