This medical light source device is worn on the body of an operator and can be set to a state in which the range of illumination is offset from the direction in which the body is currently facing. An acceleration sensor (106) is attached to a holder (7) that allows an illuminating unit (1) to be worn on the body of the operator, and the movement of the body of the operator is detected by the acceleration sensor (106). When a center position setting switch (107b) for the range of illumination is operated, a position detection unit (108) detects the center position on the basis of acceleration information detected by the acceleration sensor (106) and an optical axis adjustment unit (109) fixes the optical axis for the illuminating unit (1) to the center position that has been detected. Furthermore, the angle of illumination of the illuminating light from the illuminating unit (1) can be adjusted in a plurality of steps by an illumination control unit (110).
