A biological information reading device (1, 1a, 1b, 1c, 1d) for reading biological information, comprising: a biological signal acquisition unit configured to acquire a biological signal from a living body; an operation unit configured to perform an operation of estimating biological information based on an acquired biological signal corresponding to the biological signal acquired by the biological signal acquisition unit; and a biological information output unit configured to output estimated biological information corresponding to the biological information estimated by the operation unit to an outside of the biological information reading device, which is characterized in that the biological signal acquisition unit includes a stacked light emitting and receiving element in which a light receiving element (12, 12c), a polarizing plate (11, 11a) an organic light emitting diode implementing a linearly polarized light emitting function, and a quarter-wave plate are stacked such that linearly polarized light emitted from the organic light emitting diode is changed by the quarter-wave plate to light circularly polarized and that reflected light from the living body is changed by the quarter-wave plate to light linearly polarized in a different direction from the light emitted from the organic light emitting diode to pass through the organic light emitting diode and the polarizing plate (11, 11a) to the light receiving element (12, 12c), and a light transmissive adhesive layer is provided on a surface of the quarter-wave plate of the biological signal acquisition unit coming into contact with a skin of the living body, wherein the quarter-wave plate and the light transmissive adhesive layer have refractive indices matching with the refractive index of skin of the living body. a biological signal acquisition unit configured to acquire a biological signal from a living body; an operation unit configured to perform an operation of estimating biological information based on an acquired biological signal corresponding to the biological signal acquired by the biological signal acquisition unit; and a biological information output unit configured to output estimated biological information corresponding to the biological information estimated by the operation unit to an outside of the biological information reading device, which is characterized in that the biological signal acquisition unit includes a stacked light emitting and receiving element in which a light receiving element (12, 12c), a polarizing plate (11, 11a) an organic light emitting diode implementing a linearly polarized light emitting function, and a quarter-wave plate are stacked such that linearly polarized light emitted from the organic light emitting diode is changed by the quarter-wave plate to light circularly polarized and that reflected light from the living body is changed by the quarter-wave plate to light linearly polarized in a different direction from the light emitted from the organic light emitting diode to pass through the organic light emitting diode and the polarizing plate (11, 11a) to the light receiving element (12, 12c), and a light transmissive adhesive layer is provided on a surface of the quarter-wave plate of the biological signal acquisition unit coming into contact with a skin of the living body, wherein the quarter-wave plate and the light transmissive adhesive layer have refractive indices matching with the refractive index of skin of the living body.