A power transmitting apparatus comprising: a clutch housing rotatable together with an input member and mounted thereon a plurality of driving-side clutch discs; a clutch member mounted thereon a plurality of driven-side clutch discs arranged between the driving-side clutch discs alternately therewith and connected to an output member; and a pressure member mounted on the clutch member axially movably relative to the clutch member so that the driving-side clutch discs and the driven-side cutch discs are forced to be press-contacted each other and the press-contacting force acting on them are released in accordance with axial approach and separation of the pressure member relative to the clutch member in order to transmit a rotational driving force inputted to the input member to the output member or cut off the rotational driving force from the output member characterized in that: the power transmitting apparatus further comprises a slide-suppressing member(s) (11, 12, 13, 14, 15) for applying sliding resistance to the pressure member when the pressure member is rotated relative to the clutch member; and in that the power transmitting apparatus further comprises a press-contact assisting cam (4a, 5a) for increasing the press-contacting force acting on the driving-side clutch discs and the driven-side clutch discs by causing relative rotation of the pressure member and the clutch member and bringing them close to each other when a condition in which the rotational driving power inputted to the input member can be transmitted to the output member is attained, and a back-torque limiting cam (4b, 5b) for releasing the press-contacting force acting on the driving-side clutch discs and the driven-side clutch discs by causing relative rotation of the pressure member and the clutch member and separating them from each other when a rotational speed of the output member has exceeded that of the input member. a clutch housing rotatable together with an input member and mounted thereon a plurality of driving-side clutch discs; a clutch member mounted thereon a plurality of driven-side clutch discs arranged between the driving-side clutch discs alternately therewith and connected to an output member; and a pressure member mounted on the clutch member axially movably relative to the clutch member so that the driving-side clutch discs and the driven-side cutch discs are forced to be press-contacted each other and the press-contacting force acting on them are released in accordance with axial approach and separation of the pressure member relative to the clutch member in order to transmit a rotational driving force inputted to the input member to the output member or cut off the rotational driving force from the output member characterized in that: the power transmitting apparatus further comprises a slide-suppressing member(s) (11, 12, 13, 14, 15) for applying sliding resistance to the pressure member when the pressure member is rotated relative to the clutch member; and in that the power transmitting apparatus further comprises a press-contact assisting cam (4a, 5a) for increasing the press-contacting force acting on the driving-side clutch discs and the driven-side clutch discs by causing relative rotation of the pressure member and the clutch member and bringing them close to each other when a condition in which the rotational driving power inputted to the input member can be transmitted to the output member is attained, and a back-torque limiting cam (4b, 5b) for releasing the press-contacting force acting on the driving-side clutch discs and the driven-side clutch discs by causing relative rotation of the pressure member and the clutch member and separating them from each other when a rotational speed of the output member has exceeded that of the input member. the power transmitting apparatus further comprises a slide-suppressing member(s) (11, 12, 13, 14, 15) for applying sliding resistance to the pressure member when the pressure member is rotated relative to the clutch member; and in that the power transmitting apparatus further comprises a press-contact assisting cam (4a, 5a) for increasing the press-contacting force acting on the driving-side clutch discs and the driven-side clutch discs by causing relative rotation of the pressure member and the clutch member and bringing them close to each other when a condition in which the rotational driving power inputted to the input member can be transmitted to the output member is attained, and a back-torque limiting cam (4b, 5b) for releasing the press-contacting force acting on the driving-side clutch discs and the driven-side clutch discs by causing relative rotation of the pressure member and the clutch member and separating them from each other when a rotational speed of the output member has exceeded that of the input member.