To provide a torque converter capable of easily changing a power transmission capacity while suppressing the resistance in the power transmission from increasing.

The torque converter comprises a turbine runner moving mechanism 40 capable of moving a turbine runner 23. The turbine runner 23 is moved according to the state of an engine 5 by the turbine runner moving mechanism 40. Thereby, when power is transmitted from a pump impeller 21 to the turbine runner 23 via oil, the transmission capacity can be changed without increasing the resistance in the power transmission. When the power transmission capacity is changed in such a manner, the power transmission capacity is changed by moving the turbine runner 23, so that the transmission capacity can be easily changed. As a result, the power transmission can be easily changed while suppressing the resistance in the power transmission from increasing.