To provide a movable body driving unit for a vehicle, which enables the pinching of foreign matter by a movable body to be detected with a high degree of accuracy, for example, even if a power supply voltage fluctuates or even if an opening/closing speed of the movable body fluctuates depending on a moving position of the movable body.

This movable body driving unit S is equipped with a motor 11 for moving a movable floor 65, a current detector 21 and a rotation detector 22, a microcomputer 31, and a battery 41. The microcomputer 31 sets a reference threshold, and sets an auxiliary threshold on an auxiliary reference line which makes the adjacent reference thresholds connected together by a straight line or an approximated curve. The microcomputer 31 makes it determined that the pinching occurs when a motor driving current value exceeds the reference threshold or the auxiliary reference value. Additionally, the microcomputer 31 adjusts a motor driving voltage so that the motor driving voltage supplied to the motor 11 can be set constant, even if the power supply voltage fluctuates.