A mark forming method for a moving body is disclosed. The method includes the steps of forming a second material layer, which scatters second wavelength light by being dispersed a first material that has a light absorbing property for first wavelength light therein, on a moving body; irradiating the first wavelength light on a part of the second material layer, making the first material at the part absorb the first wavelength light, and changing a scattering property of the part of the second material layer; and forming a mark whose scattering property for the second wavelength light is different in the part.