An experimental setup is presented, which allows simultaneous thermogravimetry-mass spectrometry (TG-MS) investigations of air-sensitive compounds in argon. The setup consists of a commercially available thermobalance with mass spectrometer and a glove box. Modifications needed for installations within the glove box are summarized. The performance with respect to e.g. the background gas level and the stability of the TG signal is given together with an additional list of limitations caused by the specific conditions (Ar, temperature range 20-1200 degrees C). The proper function of the new setup up to 800 degrees C is demonstrated by the thermal decomposition of CuCl2 center dot 2H(2)O. (C) 2011 Elsevier B.V. All rights reserved.