An image analysis apparatus includes: a distribution data generator that generates, on the basis of a sample image obtained by irradiating a biological tissue with light having an infrared bandwidth, distribution data indicating a distribution of light intensity in the infrared bandwidth in the tissue a differential calculator that calculates, on the basis of the distribution data, an Nth-order derivative of the distribution of the light intensity in a first wavelength band in the infrared bandwidth, where N is an integer of 2 or more, for each region in the sample image and an image data generator that converts the Nth-order derivative into a gray-scale value to generate image data.
