The purpose of the present invention is to provide a medical light source device that can assure long illumination time necessary in surgery at a medical site. This medical light source device is mounted on the body of an operator and shines light on a surgical site. An illuminating part (81) is mounted on the body of the operator by a holding frame (7), and an acceleration sensor (80) that detects the movements of the operator is provided. A control unit (84) controls the current to the illuminating part (81) from a power supply unit and also controls reductions in the brightness of the illuminating part (81) or stops the flow of electricity to the illuminating part (81) when the acceleration sensor (80) detects acceleration of a prescribed value or higher.
