PURPOSE: To offer the deice which can evaluate quantitatively a living body rhythm curve.

CONSTITUTION: The device is constituted of a rhythm curve input means 1 for inputting a living body rhythm curve, a feature parameter input means 2 for inputting a feature parameter of the living body rhythm curve, a deciding means 3 for evaluating the living body rhythm curve by using at least one of a statistical waveform analyzing method and a pattern matching method, based on an input result of each input means 1, 2, and an output means 4 for outputting a result of evaluation by the deciding means 3. In such a way, since the living body rhythm curve is evaluated by using at least one of the statistical waveform analyzing method and the pattern matching method, based on the living body rhythm curve and its feature parameter, the living body rhythm curve can be evaluated quantitatively.