The endoscope apparatus includes an illumination unit for irradiating at least three kinds of illumination light having different wavelengths including standard light, first and second reference light onto a biological object, a switching unit for periodically switching the illumination light, an imaging unit for capturing image data by the illumination light in each imaging frame, and an acquisition unit for acquiring biological function information from the captured image data. The irradiation order of illumination light is switched at least in order of the first reference light, the standard light and the second reference light, a standard image by the standard light and reference images by the reference light are acquired, and the biological function information is calculated based on the standard image and the reference images.
