Among first and second stators (40, 41) of a torque converter supported on a fixed part by a one-way clutch corresponding to the stators, the number of second stator blades (46) of the second stator (41) on the downstream side in the direction of flow of oil is larger than the number of first blades (42) of the first stator (40) on the upstream side, and the maximum value t2 for blade thickness of the second stator blade (46) is smaller than the minimum value t1 for blade thickness of the first stator blade (42). Therefore, it is possible to ensure that there is a sufficient gap (²) between a trailing edge (42b) of the first stator blade (42) and a leading edge (46a) of the second stator blade (46), thus preventing the flow of oil from being stopped by the gap (²), and it is possible to align effectively the flow of oil by means of the second stator blades (46), which are larger in number, thereby achieving a balance between improvement of the torque ratio and improvement of the capacity coefficient of the torque converter.