Among first and second stators of a torque converter supported on a fixed part by a one-way clutch corresponding to the stators, the number of second stator blades of the second stator on the downstream side in the direction of flow of oils larger than the number of first blades of the first stator on the upstream side, and the maximum value t2 for blade thickness of the second stator blade is smaller than the minimum value t1 for blade thickness of the first stator blade. Therefore, it is possible to ensure that there is a sufficient gap (β) between a trailing edge of the first stator blade and a leading of the second stator blade, thus preventing the flow of oil from being stopped by the gap (β), and it is possible to align effectively the flow of oil by means of the second stator blades.