According to one embodiment, a transmission/reception unit generates a reception signal. A signal extraction unit extracts a harmonic signal and fundamental wave signal from the reception signal. A calculation unit calculates a feature amount based on values corresponding to the amplitudes of the harmonic signal and fundamental wave signal. An area determination unit determines an area in a scanned area based on the feature amount and a predetermined threshold. A change unit changes the value corresponding to the amplitude of the harmonic signal in the determined area. An image generation unit generates a corrected harmonic image based on the harmonic signal in the scanned area including the determined area having the changed value.