A reaction-type turbine according to the present invention is configured in that a portion of a rotary shaft module which penetrates through a side with an inlet portion of a housing has a diameter larger than the diameters of other portions. Thus, the pressurized area in which a working fluid applies pressure to a rotary shaft in the direction opposite to the working fluid flow direction increases, thus increasing force in the direction opposite to the working fluid flow direction. As a result, axial direction force applied to the rotary shaft in the working fluid flow direction may be reduced. Therefore, the reaction-type turbine of the present invention has the advantages of eliminating the necessity of installing a separate thrust bearing for supporting axial force in the working fluid flow direction.