The neck joint unit 280 includes a rotary joint 281 in the yaw direction (rotated around the Z-axis), a rotary joint 282 in the pitch direction (rotated around the Y-axis) and a rotary joint 283 in the roll direction (rotated around the X-axis), and thus has 3 degrees of freedom.Motors (for example, actuators such as electric motors and hydraulic motors) to rotate the head 104 are connected to the