Abstract: The organic heteropolymer of this invention is useful for forming an organic semiconductor and is a copolymeric heteropolymer having a constitutional unit represented by the formula (1) and a constitutional unit represented by the formula (2): wherein M1 and M2 each represent a heteroatom selected from a group 8 element, a group 9 element, a group 10 element, a group 14 element, a group 15 element, and a group 16 element of the Periodic Table, and are different in group; M1 and M2 each have a valence v of 2 to 6; R1a and R1b each represent a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group; R2a and R2b each represent a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group, a univalent or bivalent heteroatom selected from a group 16 element and a group 11 element of the Periodic Table, or a metal atom forming a complex with a ligand; m1, m2, n1, and n2 each denote 0 or 1; a ring Ar represents an aromatic ring; R3 represents a straight- or