A technology is disclosed which provides an array scanning type ultrasound probe capable of preventing a diminution of ultrasound of a piezoelectric device at the time of transmission and at the time of reception due to its damage and thereby reducing a sensitivity deterioration of a diagnostic image. According to the technology, included are an electroacoustic conversion unit formed by arranging multiple piezoelectric devices and multiple acoustic matching layers in a predetermined direction, each of the multiple piezoelectric devices being an electroacoustic conversion device, the multiple acoustic matching layers being respectively stacked on the multiple piezoelectric devices; and a signal flexible board transferring electric signals to be transmitted to and received from the multiple piezoelectric devices. An incision passing through the multiple piezoelectric devices in respective thickness directions of the piezoelectric devices and extending into the corresponding acoustic matching layers stacked thereon is provided in parallel to the arrangement direction.