An opening-closing body drive device includes a motor for opening and closing an opening-closing body, and a control unit to control driving the motor. The control unit recognizes a constraint position of the motor during a closing operation as a reference position and executes pinching processing in a section that is from the reference position to a prescribed position in the opening direction side and that excludes a mask section. The control unit updates the reference position when the motor constraint position is nearer to the closed direction side than a set position that is set in the mask section and does not update the reference position when the motor constraint position is nearer to the open direction side than the set position.