An endoscope light source apparatus configured to control a turret provided with optical filters for transmitting an illuminating light, comprising: a turret provided rotatably about an axis and including, on a circumference of the turret, a plurality of optical filters (341, 342) for transmitting the illuminating light and a plurality of corresponding detection bodies disposed respectively for the plurality of optical filters (341, 342); an instruction section configured to receive an operation instruction for designating an optical filter (341, 342) among the plurality of optical filters (341, 342) to enter an optical path; a drive section configured to rotatably drive the turret; and a first detector configured to detect a rotation angle of the turret and output a detection signal corresponding to a result of the detection; characterized in that the endoscope light source apparatus further comprises: a second detector configured to optically detect a position of the detection bodies in a second rotational angle range narrower than a first rotational angle range detected by the first detector for allowing the designated optical filter (341, 342) to enter the optical path; and a turret control section configured to, after rotationally moving, in response to the operation instruction, the turret about the axis so that a value of the detection signal detected by the first detector falls within the first rotational angle range corresponding to the designated optical filter, rotationally move the turret about the axis until a detection body corresponding to the designated optical filter (341, 342) among the plurality of detection bodies is detected in the second rotational angle range detected by the second detector which is narrower than the first corresponding to the designated optical filter range in order to position the optical filter (341, 342) designated in response to the operation instruction, and stop the turret in response to detection of the detection body corresponding to the designated optical filter (341, 342). a turret provided rotatably about an axis and including, on a circumference of the turret, a plurality of optical filters (341, 342) for transmitting the illuminating light and a plurality of corresponding detection bodies disposed respectively for the plurality of optical filters (341, 342); an instruction section configured to receive an operation instruction for designating an optical filter (341, 342) among the plurality of optical filters (341, 342) to enter an optical path; a drive section configured to rotatably drive the turret; and a first detector configured to detect a rotation angle of the turret and output a detection signal corresponding to a result of the detection; a second detector configured to optically detect a position of the detection bodies in a second rotational angle range narrower than a first rotational angle range detected by the first detector for allowing the designated optical filter (341, 342) to enter the optical path; and a turret control section configured to, after rotationally moving, in response to the operation instruction, the turret about the axis so that a value of the detection signal detected by the first detector falls within the first rotational angle range corresponding to the designated optical filter, rotationally move the turret about the axis until a detection body corresponding to the designated optical filter (341, 342) among the plurality of detection bodies is detected in the second rotational angle range detected by the second detector which is narrower than the first corresponding to the designated optical filter range in order to position the optical filter (341, 342) designated in response to the operation instruction, and stop the turret in response to detection of the detection body corresponding to the designated optical filter (341, 342).