Provided are a sleep sufficiency estimation device and a sleep sufficiency estimation method which can estimate a subject's sleep sufficiency. This sleep sufficiency estimation device 1 includes: a storage unit 6 which stores a plurality of functions that accord with a subject's characteristics and to sleep sufficiency zones divided according to sleep sufficiency; and a sleep sufficiency estimation unit 5 which determines an initial value of sleep sufficiency from the subject's maximum sleep time and initial sleep time, the subject's self-evaluation, or data obtained from a source other than the subject and estimates the subject's sleep sufficiency by calculating, using the functions selected according to the sleep sufficiency zone to which the subject's sleep sufficiency belongs and a characteristics data representing the subject's characteristics, an increase/decrease in the sleep sufficiency depending on the subject's sleep time or waking time.
SLEEP SUFFICIENCY ESTIMATION DEVICE AND SLEEP SUFFICIENCY ESTIMATION METHOD