PROBLEM TO BE SOLVED: To acquire desired information of a biological tissue in a further clear state suited for a diagnosis when observing the biological tissue by white light and special light.SOLUTION: An endoscope apparatus includes: a first light source 51 defining a semiconductor light-emitting element as a light-emitting source a second light source 53 defining a semiconductor light-emitting element having a different light emission wavelength from that of the first light source 51, as a light-emitting source a wavelength conversion member 57 excitingly emitting light by outgoing light from at least one of the first light source 51 and the second light source 53 and light quantity rate change means 55 for changing a light quantity rate of the outgoing light from the first light source 51 and the outgoing light from the second light source 53. The endoscope apparatus optionally generates the outgoing light from the first light source 51 and the outgoing light from the second light source 53 to provide illumination light suited for the diagnosis according to absorption characteristics and scatter characteristics of a biological tissue. This configuration can thus acquire desired tissue information of the biological tissue in a further clear state.SELECTED DRAWING: Figure 2