In a rotating machine such as a gas turbine, a steam turbine, and a compressor, a shaft sealing device that seals a periphery of a rotating shaft, disclosed in Japanese Patent Publication No. 2011-185219, is known. The shaft sealing device disclosed in Japanese Patent Publication No. 2011-185219 includes a plurality of leaves (thin plates) to be arranged in the periphery of the rotating shaft and side seal plates (side leaves) to be arranged each in a high pressure space and a low pressure space divided by the leaves. During stoppage of the rotating shaft, a tip (inner side end) of each leaf is in contact with an outer peripheral surface of the rotating shaft. During rotation of the rotating shaft, the tip of the leaf is displaced away from the rotating shaft, and the leaf and the rotating shaft are not in contact with each other. Each side seal plate approaches a side end of the leaf by an action of pressure and suppresses an excess inflow of an operating gas in the high pressure space among the leaves.