Endoscope

An endoscope for observing a subject in which a dye is dispersed, the dye being a material having a light absorbing wavelength region and a light transmission wavelength region in a visible light wavelength region, the endoscope comprising:

• a controller comprising hardware, the controller being configured to switch observation modes, the observation modes including a dye valid observation mode for acquiring an image in which the dye is visually recognized, and a dye invalid observation mode for acquiring an image in which the dye is substantially not visually recognized;
• wherein the controller selectively emits illumination lights in accordance with switching of the observation modes by the observation mode switch;
• the illumination lights include a dye valid illumination light that is sent out when the dye valid observation mode is selected, and a dye invalid illumination light that is sent out when the dye invalid observation mode is selected,
• the dye valid illumination light includes a visible light of a wavelength out of the main absorbing wavelength region of the dye, and a light of a wavelength in the main absorbing wavelength region of the dye, and
• the dye invalid illumination light includes a visible light of the wavelength out of the main absorbing wavelength region of the dye, but does not include a light of the wavelength in the main absorbing wavelength region of the dye.