A phase change material is used for the production of a sterile state indication means for a sterilization container. A sterile state indication means for a sterilization container includes a fluid-tight case containing a phase change material. In this assembly, the case wall of the case includes at least one transparent zone and an activator which can be actuated in order to release an activation energy and/or crystallization seeds. The activator is in contact with the phase change material. Further, a sterilization container includes a container trough and a container lid, including a sterile state indication means. The sterile state indication means is provided either on the container trough or on the container lid, and the activator, in the closed state of the sterilization container, is in direct or indirect connection with the respectively other element among container trough and container lid.