PURPOSE: To perform mechanical and specified control of creep torque during idle running, by providing a hydraulic control valve which exerts a deferential pressure between an oil chamber on the positive drive side, facing the rotation direction of an input disc, and an oil chamber on the reverse drive side positioned reverse to aforesaid oil chamber against the spring load of a spring.

CONSTITUTION: During idling, a duty ratio D of a solenoid valve 171 is low, and an output oil pressure P5 is guided from a creep control valve 160 to a starting clutch 40. Namely, since the output oil pressure P5 of a creep control valve 160 is controlled such that the more a difference between an oil pressure P1 of positive drive oil pressure chambers 75 and 76 and an oil pressure P2 of oil chambers 74 and 77 on the reverse drive side is increased, the more an output oil pressure P5 of a creep control valve 160 is decreased, with the decrease in input torque, transmission torque of the starting clutch 40 is increased, and creep torque is automatically regulated to a specified value responding to the magnitude of the spring load of a spring 161. This constitution enables maintenance of creep torque to a normally specified value irrespective of unevenness in the spring load of the return spring of the starting clutch 40, unevenness in its surface pressure, and a fluctuation in a friction factor due to a change in an oil temperature.