1. An apparatus for recognizing an emotion, the apparatus comprising: an input signal generation unit configured to receive a plurality of heart rate data, and generate input signals, each having a sequence; a signal classification unit configured to classify the input signals into groups; and an emotion recognition unit configured to search for a group, to which the input signal generated by the input signal generation unit belongs, among the groups classified by the signal classification unit, and recognize a user emotion corresponding to the found group.