NOVELTY - Substrate having rod-like molecules on its surface comprises: a substrate in which a pattern including a convex portion with a flat upper surface is formed on its at least portion; and many rod-like molecules, which are formed into rod-like shape, are aligned in line in a direction crossing a molecular length direction of each of the rod-like molecules on the upper surface of the convex portion, and have liquid crystalline states. The molecular length (L1) of the rod-like molecule is less than or equal to 2 times L2 (a length of the rod-like molecule in the molecular length direction within the convex portion).    USE - The substrate having rod-like molecules on its surface is useful in: functional materials having ultra micro structures e.g. an ultra micro electronic circuit and a photoelectric conversion material; and a material of a solar cell, photocatalyst, inorganic luminescent material, carbon nanotube composite field emission device, chemical sensor and biochip.    ADVANTAGE - The substrate: has rod-like molecules on its surface, having an aspect ratio (which is molecular length/diameter) of greater than or equal to 4, which exhibit a liquid crystalline state (claimed); produces easily a large area ultra thin film of rod-like molecules with a uniaxial orientation with a simple method e.g. drop-casting method; and has a fine line structure that is formed by self-organized rod-like molecules directed to a certain direction.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a method (m1) for producing the substrate having rod-like molecules on its surface, comprising: (a) allowing a solution or a dispersion liquid containing rod-like molecules that exhibit liquid crystalline states to flow on the surface of the substrate in which a pattern including a convex portion with a flat upper surface is formed on its at least portion of the surface; and (b) adsorbing the rod-like molecules on the upper surface of the convex portion so that the rod-like molecules are aligned in line in a direction crossing the molecular length direction of each of the rod-like molecules;    (2) a method (m2) for adsorbing rod-like molecules on the surface of a substrate, comprising the steps (a) and (b) as above per se; and    (3) a method (m3) for narrowing a molecular length distribution of rod-like molecules, comprising: allowing a solution or a dispersion liquid containing rod-like molecules that exhibit liquid crystalline states to flow on the surface of the substrate in which a pattern including a line-shaped convex portion with a flat upper surface is formed on its at least portion of the surface; selectively adsorbing rod-like molecules whose molecular lengths (L1) are 0.2-2 times the width dimension (L3) of the line-shaped convex portion among the rod-like molecules contained in the solution or the dispersion liquid on the upper surface of the convex portion so that the rod-like molecules are aligned in line in a direction crossing the molecular length direction of each of the rod-like molecules; and collecting the rod-like molecules adsorbed on the upper surface of the line-shaped convex portion by separating it from the substrate after adsorbing the rod-like molecules.