An ultrasound observation apparatus for generating an ultrasound image based on an ultrasound signal acquired by an ultrasound probe, includes: a frequency analysis unit configured to analyze a frequency of the ultrasound signal to calculate a plurality of frequency spectra in accordance with reception depths and receiving directions of the ultrasound signal a feature calculation unit configured to calculate a feature of each of the plurality of frequency spectra an attenuation factor setting unit configured to set an attenuation factor of a computation-purpose region, the computation-purpose region being a region that is different from a region of interest in the ultrasound image and is used for computation for correcting the feature and a feature correction unit configured to perform attenuation correction on the feature using the attenuation factor, thereby to calculate a corrected feature at a sampling point in the region of interest in the ultrasound image.
