A micro-resonator sensor using an evanescent wave of a total reflection mirror is disclosed. A main waveguide includes an input hole to which a optical signal is inputted and an output hole from which the optical signal is outputted, and a optical coupling region at which a portion of the optical signal inputted through the input hole is branched. A resonant waveguide includes a optical coupling waveguide optically coupled with the optical coupling region of the main waveguide to receive the branch optical signal branched from the main waveguide and a plurality of circumferential waveguides. The optical coupling waveguide and the plurality of circumferential waveguides are disposed in a polygonal shape. Optical path changing units are disposed at vertex regions to which the optical coupling waveguide and the circumferential waveguides are connected to reflect at least a portion of the branch optical signal inputted to the resonant waveguide so as to turn around within the resonant waveguide. At least one of the optical path changing units disposed at the vertex regions to which the circumferential waveguides are connected is a total reflection mirror with a receptor provided on the other side from the side on which the branch signal is inputted and combining with a measurement-subject material. The circumferential waveguide that inputs the branch optical signal to the total reflection mirror is disposed such that an incident angle relative to the total reflection mirror is larger than a total reflection threshold angle. Because the resonator is configured by using the total reflection mirrors, the micro-resonator sensor can be fabricated with an ultra-compact size without an excessive radiation loss. Also, because all the elements are integrated on a single wafer, the micro-resonator sensor can be fabricated as an on-chip, whereby an ultra-compact optical sensor module applicable to mobile terminals can be manufactured.