Provided are an ultrasound diagnosis device and a program which can display good ultrasound diagnosis images. A reception unit (13) subjects a received signal obtained by means of an oscillator (2a) to sampling at a preset acquisition sampling frequency. The reception unit (13) then subjects the received signal to phasing addition at each sampling point and thereby obtains acquisition sampling data. A display unit (17) then displays an image. A control unit (18) then performs downsampling by removing data from the acquisition sampling data in such a way that a display dependent sampling frequency, which is set in accordance with the display image size of the display unit (17), is met. The display unit (17) then displays an ultrasound diagnosis image on the basis of the acquisition sampling data that has been subjected to downsampling by the control unit (18).
