A head actuator assembly of a disk device has a suspension which supports a head, an arm which supports the suspension and is rotatably supported by a bearing portion, signal wires which extend on the suspension and the arm and are connected electrically to the head, and a board unit. In manufacture, the signal wires are mounted on the suspension and the arm, and a connecting end portion of the board unit is connected to the signal wires mounted on the suspension and the arm. Thereafter, the head is mounted on the suspension and connected electrically to the signal wires.