PROBLEM TO BE SOLVED: To obtain desired tissue information of a living tissue in a clearer state suitable for diagnosis when observing the living tissue with white light or special light. A first light source 51 using a semiconductor light emitting element as a light source, a second light source 53 using a semiconductor light emitting element having an emission wavelength different from that of the first light source 51, and a first light source 51. , A wavelength conversion member 57 that is excited and emitted by light emitted from at least one of the second light source 53, and a light amount that changes the light amount ratio between the light emitted from the first light source 51 and the light emitted from the second light source 53. By including the ratio changing means 55, the emitted light from the first light source 51 and the emitted light from the second light source 53 are arbitrarily generated, and a diagnosis according to the absorption characteristic and the scattering characteristic of the biological tissue is performed. Suitable illumination light can be provided. As a result, desired tissue information of the living tissue can be acquired in a clearer state. [Selection diagram] Figure 2【課題】白色光や特殊光による生体組織の観察時に、生体組織の所望の組織情報を、診断に適したより明瞭な状態で取得する。【解決手段】半導体発光素子を発光源とする第１の光源５１と、第１の光源５１とは異なる発光波長の半導体発光素子を発光源とする第２の光源５３と、第１の光源５１、第２の光源５３の少なくとも一方からの出射光により励起発光する波長変換部材５７と、第１の光源５１からの出射光と第２の光源５３からの出射光との光量比を変更する光量比変更手段５５と、を備えることで、第１の光源５１からの出射光と第２の光源５３からの出射光を任意に発生させて、生体組織の吸収特性および散乱特性に応じた診断に適した照明光を提供できる。これにより、生体組織の所望の組織情報が、より明瞭な状態で取得可能となる。【選択図】図２
