Device for thermogravimetric analysis of catalytic gas-solid reactions Volatile materials can experience initial loss of mass during thermogravimetric analysis. A device is provided to delay the initial release of volatile material. The device comprises a container and an opening on the top part of the container. The opening is adapted to be hermetically fastened, and the opening is adapted to unfasten under pressure of vaporized material. The device can be used for analyzing catalytic gas-solid reactions in thermogravimetric analysis.