An ultrasound diagnostic apparatus includes an array transducer, a transmission driver for transmitting an ultrasonic beam from the array transducer toward a subject, a reception circuit for processing a pair of reception signals in a pair of available channels of the array transducer having received an ultrasonic echo produced by the subject, with the pair of available channels being those channels which belong to channels simultaneously made available for reception of the ultrasonic echo and are arranged symmetrically about a transmit beam axis, so as to generate reception data in one piece, and outputting the generated reception data as reception data in each of the pair of available channels, and an image generating unit for generating an ultrasound image based on the reception data outputted from the reception circuit.