A shape estimation device includes an input circuit, a storage circuit and an arithmetic circuit. The input circuit receives light amount information being a relationship between a wavelength and a light amount. The light amount information is acquired by using a sensor configured such that the light amount to be detected with respect to the wavelength corresponding to each of sensing parts varies in accordance with a shape of each of the sensing parts. The storage circuit stores a relationship among the shape, the wavelength and the light amount with respect to each sensing part. The arithmetic circuit calculates the shape of each sensing part, based on the light amount information, and a light amount estimation value being a relationship between the wavelength and the light amount.
