According to the view of the author of this paper, Prof. Belluš based his architectural creation on the relationship of the detail and the unit in his works, where both parts of architecture interfere and are mutually determined. It is inevitable to access Beluš’s detail as a part of the unit and Belluš’s concept in which he presents the main ideas of his work in the quantity of mutually determined details. Belluš’s detail has become a part of his architectural concept. On the contrary to his contemporaries, Belluš knew that the author had not only to draw his design but to build it and live with it, because he was building it for people. The details are very good for a building due to a suitable choice of high quality materials, logic of material structure, appropriate functions with subordinated design, artistic value and economic capacity. In Belluš’s works are no main or supporting things, there are only good and cultivated things, flowing from precious unity of function, technology, economy, aesthetics of the design, long-term reliability reached by a good material and perfect craftwork. All his details confirm a seal of cultivated artistic sensitivity of the architect.