The surface pressure-molecular area (pi -A) isotherms for the layers of copper porphyrazine (CuPaz) at the air-water interface are studied at different initial surface concentration (N-0) of CuPaz. A new approach to analysis of the isotherms is proposed. It allows determination of the molecular tilt angle, compressibility factor of the floating layers, the polylayer order, dimensions of the hydration sphere surrounding the spread molecules and work of transition. It is stated that the CuPaz layers are constructed from either two- or three-dimensional supermolecules. The latter are supposed to be a tilted prism with square base of four CuPaz molecules.