PROBLEM TO BE SOLVED: To provide a substrate satisfying the following conditions, that is, to control the array of the molecules by utilizing hydrophilic or hydrophobic interaction between the substrate and the molecules, to observe the arrayed molecules by a scanning tunnel microscope, (1) a clean surface of the substrate can be obtained, (2) electric resistance of the substrate is small to some extent (≤ 106 Ω cm), and (3) a hydrophilic functional group and a hydrophobic functional group are regularly arrayed in substrate molecules.

SOLUTION: A pseudo one-dimensional halogen cross-linking metal complex crystal is utilized as the substrate for fixing the array of the molecules by controlling the array.