An ultrasound unit includes an ultrasound array that has a plurality of ultrasound elements, each of which has a first principal surface that is rectangular where a transmitting and receiving portion, a signal electrode terminal, and a ground electrode terminal are arranged in a longer side direction, longer sides of the ultrasound elements being coupled, one or more short-lines that are connected to a plurality of ground electrode terminals, a ground line that is connected to the short-line, and a plurality of signal lines, each of which is connected to one of the signal electrode terminals, and adjoining ultrasound elements of the ultrasound elements are coupled such that the signal electrode terminals are arranged alternately on opposite sides in the longer side direction of the transmitting and receiving portions that are rectangular.
