To provide the search and synthesis of a new multi-based substance by a more general effective process.

Two or more phases of different compositions are formed by contact heating a plurality of species of substances selected from elements and compounds under non-equilibrium conditions and carrying out the interface reaction, and the two or more phase are used as a film and its structure is analyzed by a microscope, and further the composition analysis is carried out, and a raw material substance adjusted to a given composition is mixed into the substance of new structure and heated to covert the phase to a single phase.