An ultrasonic observation apparatus amplifies a signal of an ultrasonic wave received from a sample with an amplification factor according to a receiving depth； generates B-mode image data in which the amplitude of the signal of the amplified ultrasonic wave is converted into brightness and displayed； performs amplification-correction to make the amplification factor constant with respect to the signal of the amplified ultrasonic wave regardless of the receiving depth； calculates a frequency spectrum by analyzing the frequency of the amplification-corrected signal of the ultrasonic wave； extracts feature data of the frequency spectrum by approximating the calculated frequency spectrum； performs correction, on one of the frequency spectrum and the feature data, to reduce the contribution of the attenuation of the strength accompanying the transmission of the ultrasonic wave； and generates feature data image data to display visual information corresponding to the feature data.
