My thesis of topic is the safety of machinery. The purpose of the design task is to ensure the operation and handling of the palletizing - depalletizing production line is safe and in line with the requirements of safety directives and standards. I divided the assignment into five parts. The first is working out the safety concept which includes general requirements for the new safety system, and complies with the relevant standards. The second is the selection of protective devices (light curtain ,interlock) designed for industial applications, according to the concept. The next is designing the electrical plan, programming the safety controller, and finally checking and documenting the new system. The elements of the documentation made by me are the electrical plan, the printing view of the safety controller’s programme, emergency operation matrix and the report of the stop time measurement. These are the solution of the design task, so these are included in the appendix. Besides the description of the planning process I will review the general knowledge used to solve the problem.