Disclosed are an organic semiconductor material including a thiazole compound represented by the following general formula (1) and an organic thin-film transistor using the organic semiconductor material: A1-B1-C1  (1) wherein A1 and C1 each represent an unsubstituted or substituted thiazole ring, and B1 represents an unsubstituted or substituted benzene ring or an unsubstituted or substituted polycondensed aromatic ring. Accordingly, there are provided an organic semiconductor material having high ON current and excellent storage stability and an organic thin-film transistor using the organic semiconductor material.