The endoscope system includes an insertion unit, an optical transmission unit that is provided in the insertion unit and transmits illumination light incident on a proximal end to a distal end, light in a first wavelength band, and light in a second wavelength band. And a first lens unit that receives light in the first wavelength band and light in the second wavelength band from the light source unit and emits light with different spatial intensity distribution characteristics depending on the wavelength. A second lens unit that is provided opposite to the first lens unit and that allows light emitted from the first lens unit to enter the base end of the light transmission unit, and the first lens unit and the second lens unit. A distance adjusting unit that adjusts the distance from the lens unit, and a light amount of light in the first wavelength band and a light amount of light in the second wavelength band that are emitted from the tip of the light transmission unit have a predetermined light amount ratio. A control unit that controls a distance between the first lens unit and the second lens unit.内視鏡システムは、挿入部と、挿入部に設けられ、基端に入射された照明光を先端に伝送する光伝送部と、第１の波長帯域の光と第２の波長帯域の光とを発生する光源部と、光源部からの第１の波長帯域の光と第２の波長帯域の光とが入射され、波長に応じて異なる空間的強度分布の特性で出射する第１のレンズ部と、第１のレンズ部に対向して設けられ、第１のレンズ部から出射された光を光伝送部の基端に入射させる第２のレンズ部と、第１のレンズ部と第２のレンズ部との距離を調整する距離調整部と、光伝送部の先端から出射される第１の波長帯域の光の光量及び第２の波長帯域の光の光量が所定の光量比となるように第１のレンズ部と第２のレンズ部との距離を制御する制御部と、を有する。
