A shaft seal that is constituted by annularly arranging a plurality of seal segments in the circumferential direction of a rotating shaft, in which each seal segment has a plurality of thin plates that are provided in a predetermined arrangement in the circumferential direction of the rotating shaft, side plates that sandwich the plurality of thin plates from both sides thereof in the axial direction, and retention rings that retain the base ends of the plurality of thin plates and the base ends of the side plates; the distal ends of the thin plates protrude farther toward the rotating shaft than the distal ends of the side plates, and the protrusion length of the distal ends of the thin plates in the vicinity of the end portions in the circumferential direction where adjacent seal segments are connected is set to be less than the protrusion length of the distal ends of the thin plates that are located at the middle of the seal segment in the circumferential direction.