technology applies especially to higheralloyed steels, which are otherwise processed by pressure casting. Thixoforming runs in the die cavity. Among the advantages of this technology belongs the possibility to produce components with complicated shape in one step and to utilize lower forming forces. On the other hand, high forming temperatures and the narrow forming temperature interval can be considered as disadvantages. To reach the thixotropic behaviour necessary for obtaining the required component shape, the parameters of semi-solid state play an important role. These include, for example, the fraction of the liquid phase, the shape of solid particles and the location of the liquid phase in the structure. The tool steel was used for the development of an alternative forming process. The structures were observed using light and laser confocal microscopy. The fraction of liquid phase and the size of solid particles were evaluated via image analysis.