Abstract: Surface treatment agent with high photocatalytic and sanitary effects based on TiO2 nanoparticles comprising 10 to 500 g of TiO2 nanoparticles per 1 liter of water, and binding ingredient A, which is an inorganic binder selected from the group comprising ZnO, MgO, CaO, Ca(OH)2, Mg(OH)2, CaCO3, MgCO3, Na2CO3, K2CO3 in the amount of 0.1 to 10% by weight related to the N weight of TiO2. Agent for treatment of surfaces for application on surfaces, which comprise a minimum of 50% of substances selected from the group formed by CaCO3, MgCO3 ZnO, MgO, CaO, Ca(OH)2, Mg(OH)2 or their mixtures, where the agent contains 10 to 500 g of TiO2 nanoparticles per 1 liter of water, and optionally contains a minimum of 0.1 wt % H2CO3 related to the weight of TiO2.