A fluid evaluation apparatus (100) is provided with: an irradiator (11) configured to irradiate a fluid with light； a light receiver (21, 31) configured to receive scattered light from the fluid and configured to output a light receiving signal； and an estimator (25) configured to map an input point that is on a first plane defined by a light amount and a frequency, on a second plane defined by a flow volume (Q) of the fluid and a concentration (Ht) of the fluid, thereby estimating at least one of the flow volume and the concentration, wherein the light amount and the frequency are respectively indicated by light amount information (TDC), which indicates the light amount of the scattered light included in the light receiving signal, and by frequency information (fm), which indicates the frequency associated with a beat signal caused by a Doppler shift of the light included in the light receiving signal.
