An ultrasound probe is provided with a piezoelectric sensor module, which includes a plurality of piezoelectric elements arranged two-dimensionally and configured to generate an ultrasound beam so that the beam is reflected by a subject's body and to capture a resulting reflection signal, and a control circuit board that is electrically connected to the piezoelectric sensor module through a flexible substrate and transmits or receives a signal to or from the piezoelectric sensor module. The control circuit board is composed of a transmit-only circuit board, a receive-only circuit board, and a relay flexible substrate that electrically connects the transmit-only and receive-only circuit boards.