Provided are a spectrometer that may be easily manufactured while having high resolution and sensitivity due to reduced light loss and a non-invasive biometric sensor including the spectrometer. The spectrometer includes: a stacked light absorbing structure including a plurality of absorbing layers stacked in a vertical direction and having different absorption wavelength bands, and a plurality of tunnel junction layers respectively interposed between the plurality of absorbing layers to electrically connect the plurality of absorbing layers； and an illuminating unit configured to provide the stacked light absorbing structure with an illumination light for saturation of the plurality of absorbing layers.
