Disclosed is a shaft seal device comprising: a seal body made by layering a plurality of thin-plate seal pieces in the circumferential direction of the rotor, and a housing that is fixed to the stator, holds the seal body so as to surround the same from radially outside, and includes a first facing surface that faces the high-pressure-side edge of the seal body and a second facing surface that faces the low-pressure-side edge of the seal body. The high-pressure-side clearance between the seal body and the first facing surface is smaller than the low-pressure-side clearance between the seal body and the second facing surface, and a slope part that slopes gradually toward the high-pressure side toward the tip end, which is on the rotor side, is formed in the low-pressure-side edge of each thin-plate seal piece of the seal body.