The invention relates to a thermal insulation device (1) for thermal insulation of a metal product in a rolling mill, comprising a support element (2), on which a number of thermal insulation elements (3) is arranged. To extend the service life of such a device, the invention makes provision that at least one thermal insulation device (3) is formed by multiple side parts (4, 5, 6, 7, 8, 9), which enclose within them an accommodating space for a thermal insulation material, wherein at least two of the side parts (4, 5, 6, 7, 8, 9) are connected with each other at their adjoining side areas by a hinge-like connection (10).