An actuator includes M supports to support the rotary shaft, M being an integer equal to or more than 2; and M speed reducers. The Nth support out of the M supports is located at the opposite side of the moving body across the (N−1)th support, N being an integer which is equal to or more than 2 and equal to or less than M. The first speed reducer is connected to the moving body and the first support, receives a movement of the moving body in the axial direction as an input and drives the first support with a reduced drive force that is reduced from the input, and the Nth speed reducer is connected to the (N−1)th support and the Nth support, receives a movement of the (N−1)th support in the axial direction as an input and drives the Nth support with a reduced drive force.