A multiple disc friction clutch comprises a clutch outer for take in power, a clutch hub for take out power, friction plates, a clutch spring pressing a pressing member to the friction plates for connecting the clutch, a spring receiving member supporting the clutch spring, and a coupling hub coupled to the spring receiving member as to be integrally movable. A spline inclined against an output axis is formed in a fitting portion between the coupling hub and a tube shaft, and moves the clutch spring in an axial direction of the tube shaft to a compressing side while relatively rotating the coupling hub against the tube shaft, in the case that an engine drive torque is equal to or more than a predetermined value, thereby increasing a pressing load.