The present invention relates to a thermosetting powder paint comprising, as essential components, (A) a copolymer of particular composition composed of a glycidyl group-containing monomer, styrene and other monomer copolymerizable therewith and, as curing agents capable of reacting with the component (A) to crosslink the component (A), (B) an aliphatic polycarboxylic acid and (C) a linear anhydride of an aliphatic polycarboxylic acid; a coating method using the above thermosetting powder paint; and a coated article obtained by using the above thermosetting powder paint. The above thermosetting powder paint, when used as a paint for automobile, has excellent storage stability and gives a coating film having excellent appearance, properties, weathering resistance and yellowing resistance; therefore, the paint can be favorably used particularly as an top coat and an intermediate coat for automobile and its parts.