Disclosed is a polymer having excellent solvent resistance which can be produced by using a polycarbonate diol having a repeating unit represented by the formula (1) and/or (2), having a hydroxyl group at both termini, and having a number average molecular weight of from 300 to 50,000: wherein R1 represents a linear or branched hydrocarbon group having 2 to 50 carbon atoms; and n represents an integer of 2 to 50, wherein R2 represents a linear or branched hydrocarbon group having 10 to 50 carbon atoms.