A measuring chip comprising a dielectric block and a thin film layer formed on one surface of the dielectric block. The thin film layer is used for placing a sample thereon. The dielectric block is formed as a single block, which includes an entrance surface at which a light beam enters the dielectric block, an exit surface from which the light beam emerges, and the one surface on which the thin film layer is formed. In addition, the dielectric block is integrated with the thin film layer and formed from a resin whose photoelastic coefficient is less than 5010^-12 Pa^-1.