The project task of this master's thesis was to design a facility for the preparation of ultrapure water in the semiconductor industry with a capacity of 175 m³/h, where ultrapure water must meet the stringent requirements of relevant standards. Manufacturing processes in the semiconductor industry require vast amounts of ultrapure water at almost every stage. Treating raw water to the highest level of quality is a complex process that involves a series of purification technologies, typically consisting of pretreatment, where suspended and colloidal substances are removed, demineralization, and final removal of trace substances. In the introduction of this thesis, the requirements for the water quality level in the semiconductor industry according to ASTM standards were defined. The operation and challenges of the ultrapure water production facility in the semiconductor industry were described. Furthermore, a theoretical presentation of water treatment processes applicable to both industrial-scale facilities and smaller systems is provided. In the second part of the thesis, the facility for the production of ultrapure water in the semiconductor industry was dimensioned. The calculation of ion exchangers and membrane systems was facilitated by the computer program Wave (Water Application Value Engine) from the American company DuPont. This program aided in selecting appropriate configurations of water treatment processes while adhering to all specified equipment parameters. Calculations for technological processes not covered by this computer program were done separately. The consumption of chemicals in technological processes and the energy consumption needed to operate such a facility were presented. Finally, a technological scheme of the facility, along with a floor plan showing the equipment layout, was provided.