Abstract: A shredding machine includes a pair of juxtaposed cutting rollers for shredding paper material, a movable paper feed tray for supporting the paper material to be shredded on it, a paper feed tray drive motor capable of moving the paper feed tray between lowered and elevated positions, a paper feed mechanism and a control circuit for controlling the shredding operation. The paper feed mechanism comprises paper feed rollers for feeding the paper material from the paper feed tray towards the cutting rollers, a paper feed roller drive motor for driving the paper feed rollers and an actuator for detecting the position of the uppermost paper of a stack of papers placed on the paper feed tray. The operation of the paper feed mechanism is interrupted in the case where the actuator is not activated by the stack of papers over a predetermined period of time. Abnormal conditions of the drive motors can be detected by the control circuit on the basis of an electric voltage being supplied to each motor.