A substrate excellent in weatherability and adhesion to a coating applied thereon is provided. The substrate contains (a) 100 parts by mass of a polyolefin resin, (b) 0.01 to 0.5 parts by mass of an aromatic phosphoric ester metal salt having general formula (1), and (c) 0.02 to 0.5 parts by mass of a hindered amine compound, preferably a compound having general formula (2), and optionally preferably (d) 0.02 to 0.5 parts by mass of a benzoate light stabilizer having general formula (4). The structures of general formulae (1), (2), and (4) are as defined in the description.