A sleep state determination apparatus includes: a measurement unit which measures biological information and a determination unit which calculates a first index in accordance with an activity of a first autonomic nerve and a second index in accordance with an activity of a second autonomic nerve, based on the biological information which is measured by the measurement unit, derives first variation information which indicates a variation of the first index and a second variation information which indicates a variation of the second index, and determines whether a sleep state indicated by the biological information is REM sleep or non-REM sleep, based on the first variation information and the second variation information.
