PROBLEM TO BE SOLVED: To provide a light source device for an endoscope capable of maintaining a state in which an amount of light emitted to an endoscope satisfies a predetermined condition even when a temperature changes.SOLUTION: R, G, and B laser beams of R_LD 27R, G_LD 27G, and B_LD 27B are branched into a monitoring laser beam and an irradiation laser beam irradiated on a scan type endoscope side through branching filters 31R, 31G, and 31B. Control is executed to cause an amount of the branched monitoring laser beam to be a monitoring light amount value reflecting a value of the branching rate when a temperature changes, by R, G, B drive currents to emit the R_LD 27R, G_LD 27G, and B_LD 27B so that the light amount of the irradiation laser beam falls within a range that satisfies a predetermined condition.SELECTED DRAWING: Figure 2【課題】温度が変化した場合においても内視鏡に出射される出射光の光量が所定条件を満たす状態を維持できる内視鏡用光源装置を提供する。【解決手段】Ｒ＿ＬＤ２７Ｒ，Ｇ＿ＬＤ２７Ｇ，Ｂ＿ＬＤ２７ＢのＲ，Ｇ，Ｂレーザ光は、分波器３１Ｒ，３１Ｇ，３１Ｂを経て監視レーザ光と、走査型内視鏡側に照射される照射レーザ光とに分岐し、分岐した監視レーザ光の光量が、温度が変化した場合の分岐比の値を反映した監視光光量値となるように、Ｒ＿ＬＤ２７Ｒ，Ｇ＿ＬＤ２７Ｇ，Ｂ＿ＬＤ２７Ｂを発光させるＲ，Ｇ，Ｂ駆動電流により制御することにより、照射レーザ光の光量を所定の条件を満たす範囲内にする。【選択図】図２
