The article is focused on the issue of the automatic tool change (ATC). The discussed topic can be onsidered at present to be the most relevant for the group of machines from the category of milling centres. The pressure for productivity, efficiency of the whole manufacturing process, reliability and, last but not least, safety, leads manufacturers to design and install modern equipment for the implementation of automatic tool change which fulfil the most strict requirements. Today, the most problematic area of used equipment for ATC is the manipulator ensuring the change of the tool between the spindle and the magazine. The kinematic arrangement and constructional solution of individual elements very significantly influence the dynamism of the whole process of change of the tool. Therefore, the work is focused just to the resolution of the issue of manipulators. The main results of the solution are the construction design of several types of manipulators, some of which were implemented within the project 1.2.4 in the Brno workplace RCMT (Research Centre of Manufacturing Technology) in the form of testing stands. Simulation models were created for selected types; for whose verification results of measurements from real equipment were used. On the basis of the solution of this issue, further key problem was identified related not only to the process of replacement, but also the complex problem of the service life of the spindle. It concerns the problem of the force originated during the process of the clamping of the tool. The article outlines possibilities for further research concerning the influences of these forces on the service life of the spindle (mainly service life of the bearing groups of the bedding of the spindle).