An endoscope light source apparatus includes a turret provided with a first optical filter and a second optical filter for transmitting an illuminating light, an instruction section in which an operation instruction of the turret is inputted, a drive section that drives the turret, a first detector that detects a position of the turret, a first detected portion for identifying a position of the first optical filter, a second detected portion for identifying a position of the second optical filter, a second detector that optically detects a position of the first or the second detected portion, and a turret control section that outputs a drive signal to the drive section to move the turret until the first or the second detected portion is detected by the second detector and stop the turret in response to the first or the second detected portion being detected.