A fluid assessment apparatus (1) has an irradiating device (11) irradiating measurement target (100) in which a fluid flows with a laser light (LB) a light receiving device (12) which is capable of receiving the laser light with which the measurement target is irradiated a first calculating device (143) which calculates a concentration (N) of the fluid from a first received light signal based on a signal intensity of a received light signal which the light receiving device receives and a second calculating device (146) which calculates at least one of a flow volume (Q) of the fluid and a flow velocity (v) of the fluid from (i) a second received light signal based on a variation of a frequency of the received light signal which is caused by a Doppler shift of the laser light with which the measurement target is irradiated and (ii) the concentration which the first calculating device calculates.
