A light source device for endoscope includes a rotational body configured to rotate with a rotational axis as a center; a fluorescent body arranged in a predetermined area of the rotational body and configured to generate fluorescence by excitation light being radiated; an illuminating portion capable of selectively radiating excitation light of a first quantity and excitation light of a second quantity which is larger than the first quantity to a fluorescent body; and a control portion configured to switch between a first state of radiating the excitation light of the first quantity to the fluorescent body arranged in a first area and a second state of radiating the excitation light of the second quantity to the fluorescent body arranged in a second area.