Disclosed is a phasing adder including delay charge transfer units including holding and transferring units which obtain signal charge amounts that are not amplified and which send and receive the signal charge amounts across a predetermined plurality of stages while holding the signal charge amounts for a predetermined time in each stage and a delay adder which performs phasing addition of the signal charges which are held for a predetermined number of stages in the delay charge transfer unit, and electric capacity of each first holding unit, which is the first stage among the plurality of stages in the holding and transferring unit, where the signal charges are obtained and held at a time of ultrasound wave reception is greater than electric capacity of each of later holding units where the signal charges are to be held in a second stage and stages thereafter.
