An ultrasound observation apparatus according to the present invention includes: a feature calculation unit that calculates features of a plurality of frequency spectra obtained by analyzing the frequency of an ultrasound signal an attenuation factor setting unit that, in each divided region obtained by dividing an ultrasound image into a plurality of regions, uses a plurality of attenuation factor candidate values per unit length and per unit frequency that give different attenuation characteristics to calculate a preliminarily corrected feature of each frequency spectrum for each attenuation factor candidate value by performing attenuation correction that removes the influence of the ultrasound on the feature of each frequency spectrum, and sets an optimum attenuation factor for an observation target from the plurality of attenuation factor candidate values and a feature correction unit that calculates a cumulative attenuation factor per unit frequency at a sampling point, using an optimum attenuation factor of a divided region present between a surface of the ultrasound transducer and the sampling point, and performs attenuation correction on the features using the cumulative attenuation factor to calculate a corrected feature.
