A testing device for a torque converter having a turbine portion 2 and a stator portion 3, including a turbine shaft 4 rotatably supported by a first support portion 6, and a stator shaft 9 concentrically disposed on an outer circumferential side of the turbine shaft 4 and axially moveably and non-rotatably supported by a second support portion 8. The turbine shaft 4 has a central oil passage 4b and a splined portion 4a on the outer circumferential periphery which is engaged with a splined portion 2a of the turbine portion 2 when the turbine shaft 4 is axially downwardly moved. The stator shaft 9 has a splined portion 9d on the outer circumferential periphery which is engaged with a splined portion 3a of the stator portion 3 when the stator shaft 9 is axially downwardly moved. A spring 11 is provided, which biases the stator shaft 9 toward the torque converter.