A compact apparatus of measuring biological information using light capable of measuring biological information with high reproducibility and accuracy is provided. The apparatus of measuring biological information using light comprises a light source part irradiating an organism, a light receiving part receiving light propagating from the light source part through the inside of the organism and outgoing from the surface of the organism, a forming part forming the surface of the organism into a predetermined shape by applying a pressure thereto, and a calculation part calculating information of the relation between the amount of received light and the biological information of the organism previously determined based on the amount of light received in the light receiving part.