The acoustic wave processing device includes a data processing unit which performs superimposition processing on first element data or first reception data generated by performing phasing addition on the first element data to generate processed data, an image generation unit which generates a B mode image based on the first element data and the processed data, a bloodstream image generation unit which generates a bloodstream image based on bloodstream information included in the first element data, a region setting unit which sets a bloodstream image region, a processing region setting unit which sets a region for processing in the data processing unit based on information relating to the bloodstream image region, and a display image generation unit which generates a synthesized image of the B mode image and the bloodstream image.