Medical instrument

A medical instrument, comprising:

• illumination means that switchably irradiates normal light and light of two narrow bands for observing a blood vessel in accordance with a depth of a living body mucous membrane onto living tissue, and also irradiates light of a third narrow band that has a wavelength band that is different from the two narrow bands of light and that is selected based on spectral characteristics of an observation object other than the living tissue and spectral characteristics of hemoglobin in the living tissue;
• image signal generation means that generates an image signal of the normal light and an image signal of the special light based on an output of image pickup means that picks up an image of returning light of light that is irradiated onto living tissue by the illumination means;
• color discrimination means that discriminates a color tone for respective pixels in accordance with a luminance level of image signals of the light of two narrow bands and the light of a third narrow band, and discriminates whether or not the respective pixels correspond to an observation object other than the living tissue;
• and
• color correction means that, in an observation mode that uses the special light, based on a discrimination result of the color discrimination means, performs color correction with respect to a color of an observation object other than the living tissue so that the color of the observation object other than the living tissue is similar to a color thereof in an observation mode that uses the normal light.