To provide polyester fiber paper for thermal stencil paper consisting of 100% polyester fibers, which exerts the good property of lamination on a thermoplastic resin film, exhibits excellent image clarity, and reduces a void.

This polyester fiber paper for the thermal stencil paper comprises oriented polyester fibers A with a single-fiber fineness of 0.01-0.6 decitexes, polyethylene terephthalate-based oriented polyester fibers B wherein a 2-6 mol% 5-sodium sulfoisophthalic acid with a single-fiber fineness of 0.01-0.6 decitexes and a birefringence index of 0.01-0.05 is copolymerized, and polyethylene terephthalate-based non-oriented polyester fibers C wherein a 2-6 mol% 5-sodium sulfoisophthalic acid with a single-fiber fineness of 0.5-1.5 decitexes and a birefringence index of 0.005-0.02 is copolymerized.