According to an aspect of the present invention, a turbine apparatus includes a shaft; a turbine disk provided on the shaft and having a plurality of protrusions protruding in a direction of the shaft; blades provided on the turbine disk; a support plate provided on the turbine disk and having a plurality of latching portions engaged with the plurality of protrusions; a plurality of first fixing blocks located between the plurality of latching portions; and a second fixing block located between the plurality of protrusions and fixed to the plurality of first fixing blocks, wherein a width of a space where the second fixing block is located, from among spaces between the plurality of protrusions, is less than a width of a space where the plurality of first fixing blocks are located, from among spaces between the plurality of latching portions.