A tuned cradle type damping deice which can be tuned with low-order (e.g., 1 Hz or lower) vibration, and exhibits higher performance for maintenance and inspection with a simple constitution than a conventional one. This tuned cradle type damping device comprises: a support having a circular-arc support surface which is at least a part of a circle; two swings positioned on both outsides of a center axis extending direction of the circular-arc support surface of the support; and two rollers which are rotatably supported on the circular-arc support surface to be rolled thereon and moved around the center axis thereof, and both ends of which are rotatably connected to the two swings to support the two swings.