An illumination system includes a measurement stage on which a measurement target is located, a light-providing part having illumination sections providing multi-directional incident lights to the measurement target, a light-receiving part receiving single-directional reflection lights reflected by the measurement target according to the multi-directional incident lights, and a processing part that performs acquiring a first distribution of intensities the single-directional reflection lights with respect to the multi-directional incident lights, acquiring, from the first distribution, a second distribution of intensities of multi-directional reflections lights with respect to a single-directional incident light, and determining material of the measurement target based on parameters of the second distribution. A method of recognizing material using the illumination system and a computer readable non-transitory recording medium recording a program embodying the method are provided.