An evaluation apparatus 100 evaluates the relationship between multiple subjects 2 in communication between the subjects 2. A non-verbal information measurement unit 10 measures non-verbal information S0a and S0b respectively obtained for the multiple subjects 2a and 2b, and quantifies the non-verbal information S0a and S0b so as to generate first signals S1a and S1b each configured as a time-series signal. A waveform analyzing unit 22 generates second signals S2a and S2b for the respective subjects, each configured as a value that relates to a feature configured as non-verbal information rhythm with respect to the corresponding one of the subjects 2a and 2b. A relationship evaluation unit 24 generates a third signal S3 configured as an index that represents a mental state with respect to the relationship between the multiple subjects, based on a relative relationship between the multiple second signals S2a and S2b that correspond to the respective subjects.
