Disclosed is a fiber made of a polyester resin, wherein the polyester resin is a copolymer including a dicarboxylic acid component and a glycol component; of the dicarboxylic acid component, 80 mol % or more is accounted for by a terephthalic acid component, 4.0 to 12.0 mol % is accounted for by a cyclohexane dicarboxylic acid component, and 2.0 to 8.0 mol % is accounted for by an adipic acid component; and the glycol component contains an ethylene glycol component as a main component thereof. A polyester fiber is thereby provided which can be dyed with excellent deep color property and fastness property in dyeing under a normal pressure environment and which can offer stable quality and processing performance also by a direct spinning stretching method or other general melt-spinning methods.