A shield machine comprising: a shield machine main body including a body; a plurality of shield jacks configured to cause the shield machine main body to move ahead; and an excavator configured to excavate a natural ground on a front end side of the shield machine main body, the shield machine further comprising: a first rotating member supported at a front end side portion of the shield machine main body to be rotatable around a first center axis parallel to a central axis of the shield machine main body; a first rotating device configured to cause the first rotating member to rotate; a swinging member supported by the first rotating member so as to be swingable around a second center axis parallel to the first center axis and spaced apart from the first center axis; a swinging device configured to cause the swinging member to swing with respect to the first rotating member independently from the first rotating device; a rotary cutter head supported by the swinging member so as to be rotatable around a third center axis parallel to the second center axis and spaced apart from the second center axis, and including a plurality of cutters on an excavating surface thereof; a third rotating device configured to cause the rotary cutter head to rotate with respect to the swinging member independently from the first rotating device and the swinging device; and a controller configured to control the first rotating device, the swinging device, and the third rotating device, characterized in that: the third rotating device is an actuator including a hydraulic motor or electric motor incorporated in the swinging member; and the rotary cutter head is configured to be able to excavate the natural ground in front of a vicinity of a central axis of the shield machine main body while swinging in a direction intersecting with the central axis of the shield machine main body. a first rotating member supported at a front end side portion of the shield machine main body to be rotatable around a first center axis parallel to a central axis of the shield machine main body; a first rotating device configured to cause the first rotating member to rotate; a swinging member supported by the first rotating member so as to be swingable around a second center axis parallel to the first center axis and spaced apart from the first center axis; a swinging device configured to cause the swinging member to swing with respect to the first rotating member independently from the first rotating device; a rotary cutter head supported by the swinging member so as to be rotatable around a third center axis parallel to the second center axis and spaced apart from the second center axis, and including a plurality of cutters on an excavating surface thereof; a third rotating device configured to cause the rotary cutter head to rotate with respect to the swinging member independently from the first rotating device and the swinging device; and the third rotating device is an actuator including a hydraulic motor or electric motor incorporated in the swinging member; and the rotary cutter head is configured to be able to excavate the natural ground in front of a vicinity of a central axis of the shield machine main body while swinging in a direction intersecting with the central axis of the shield machine main body.