A power transmission apparatus comprising: a clutch member (4a, 4b) housed in a clutch housing that rotates together with an input member that rotates with a driving force of an engine of a vehicle, the clutch housing having a plurality of driving clutch plates attached thereto, the clutch member (4a, 4b) having a plurality of driven clutch plates attached thereto, the driven clutch plates being arranged alternately with the driving clutch plates, the clutch member (4a, 4b) being connected to an output member that is able to rotate a wheel of the vehicle; a pressure member movable between an operating position where the driving and driven clutch plates (6, 7) are pressed against each other so as to enable transmission of the driving force of the engine to the wheel and a non-operating position where a pressing force exerted on the driving and driven clutch plates (6, 7) is released so as to cut off transmission of the driving force of the engine to the wheel; and a centrifugal clutch means including a weight member movable from a radially inner position to a radially outer position with centrifugal force produced by rotation of the clutch housing, the centrifugal clutch means being configured to, when the weight member is located at the radially outer position, press the driving and driven clutch plates (6, 7) against each other so as to enable transmission of the driving force of the engine to the wheel and configured to, when the weight member is located at the radially inner position, release the pressing force exerted on the driving and driven clutch plates (6,7) so as to cut off transmission of the driving force of the engine to the wheel, wherein the centrifugal clutch means includes a pressing member to press the driving and driven clutch plates (6, 7) against each other by moving in a stacking direction of the driving and driven clutch plates (6, 7) in response to movement of the weight member from the radially inner position to the radially outer position, characterized in that the pressing member includes an inclined surface that guides movement of the weight member, in a cross section along an axis of the output member, a straight line passing through the pressing member and parallel to the axis passes through a pressing surface of the driving clutch plate and the driven clutch plate and the inclined surface. a clutch member (4a, 4b) housed in a clutch housing that rotates together with an input member that rotates with a driving force of an engine of a vehicle, the clutch housing having a plurality of driving clutch plates attached thereto, the clutch member (4a, 4b) having a plurality of driven clutch plates attached thereto, the driven clutch plates being arranged alternately with the driving clutch plates, the clutch member (4a, 4b) being connected to an output member that is able to rotate a wheel of the vehicle; a pressure member movable between an operating position where the driving and driven clutch plates (6, 7) are pressed against each other so as to enable transmission of the driving force of the engine to the wheel and a non-operating position where a pressing force exerted on the driving and driven clutch plates (6, 7) is released so as to cut off transmission of the driving force of the engine to the wheel; and a centrifugal clutch means including a weight member movable from a radially inner position to a radially outer position with centrifugal force produced by rotation of the clutch housing, the centrifugal clutch means being configured to, when the weight member is located at the radially outer position, press the driving and driven clutch plates (6, 7) against each other so as to enable transmission of the driving force of the engine to the wheel and configured to, when the weight member is located at the radially inner position, release the pressing force exerted on the driving and driven clutch plates (6,7) so as to cut off transmission of the driving force of the engine to the wheel, wherein the centrifugal clutch means includes a pressing member to press the driving and driven clutch plates (6, 7) against each other by moving in a stacking direction of the driving and driven clutch plates (6, 7) in response to movement of the weight member from the radially inner position to the radially outer position,