In a shaft sealing mechanism which prevents fluid from flowing in an axial direction of a rotor through an annular gap between the rotor and a stator, there are provided a high pressure side plate positioned on a high pressure side region of a plurality of sheets, and a low pressure side plate positioned on a low pressure side region of the plurality of sheets, and construction is such that in a state in which the plurality of sheets is fixed on a stator side, and when under gas pressure, the sheets make contact with each other.