Abstract: In an image forming apparatus (1), an excitation light source (10) irradiates an object with excitation light for a first fluorescence substance and excitation light for a second fluorescence substance, a notch filter (20) transmits fluorescence in a wavelength range specific to each fluorescence substance among return light from the object, an imaging unit (30) separately captures images of the fluorescence in respective wavelength ranges, and an image processing unit (40) superimposes these images.