Provided is an in vivo examination apparatus including an illumination unit emitting two types of illumination light in different wavelength bands； and an image acquisition unit having sensitivity to the wavelength bands of the two types of illumination light. Blood and background tissue have higher reflectances than a predetermined threshold to illumination light in a first wavelength band, blood has a lower reflectance than the threshold to illumination light in a second wavelength band, and a condition (R1b/R1a)>；(R2b/R2a) is satisfied, where R1a is the reflectance of the background tissue to the illumination light in the first wavelength band, R1b is the reflectance of the blood to the illumination light in the first wavelength band, R2a is the reflectance of the background tissue to the illumination light in the second wavelength band, and R2b is the reflectance of the blood to the illumination light in the second wavelength band.
