Disclosed is a rotary driving device for an optical device, comprising: a rotary shaft capable of freely rotating in place which is fixed; a first shape memory alloy wire fixed in a first direction so as to enable rotational moment to be applied to the rotary shaft, and having a property that reduces the length thereof with respect to the rotary shaft when an electric current is applied; a second shape memory alloy wire fixed in a second direction opposite the first direction so as to enable rotational moment to be applied to the rotary shaft, and having a property that reduces the length thereof with respect to the rotary shaft when the electric current is applied; and a control unit for controlling the supplying of the electric current to the first shape memory alloy wire when the rotary shaft rotates in the first direction and the supplying of the electric current to the second shape memory alloy wire when the rotary shaft rotates in the second direction.
