PROBLEM TO BE SOLVED: To provide a concentration level estimation device capable of estimating a concentration level according to individual differences with a high degree of precision.SOLUTION: A concentration level estimation device 1 for estimating a concentration level of an object person includes: a heartbeat sensor 10 for detecting the information on heartbeats from the object person a concentration level estimation part 15 for estimating a concentration level from the information on the heartbeats a collection part 12 for collecting a subjective concentration level correlated with the concentration level by the input of the object person, a reaction time, etc. a conversion part 13 for converting the subjective concentration level, the reaction time, etc. into a concentration level and a learning part 14 for learning the heartbeat information corresponding to the input subjective concentration level, the reaction time, etc. and the concentration level converted by the conversion part 13 as learning data. The concentration level estimation part 15 estimates the concentration level from the heartbeat information using the result of the learning at the learning part 14.
