An optical scanning device, comprising: a light source (1; 1-1 to 1-3) capable of changing a wavelength or a phase of a light to be output; an optical mode converter (5; 5-1 to 5-3) connected to an optical waveguide through which the light output from the light source (1; 1-1 to 1-3) transmits, and configured to radiate the light received through the optical waveguide; a mirror arranged around the optical mode converter (5; 5-1 to 5-3), and configured to reflect the light radiated from the optical mode converter (5; 5-1 to 5-3) and then reflected from an object, toward an optical receiver; and an actuator having a first planar portion, a second planar portion, and a third planar portion, wherein the second planar portion has a hole in which the first planar portion is disposed, and the third planar portion has a hole in which the second planar portion is disposed, wherein the third planar portion supports the second planar portion via a first shaft, and is connected to the second planar portion via the first shaft and rotatable about the first shaft, the second planar portion supports the first planar portion via a second shaft substantially perpendicular to the first shaft, and is connected to the first planar portion via the second shaft and rotatable about the second shaft, the first planar portion holds the optical mode converter (5; 5-1 to 5-3) and the mirror, the optical mode converter (5; 5-1 to 5-3) is configured to change a radiation direction of the light to be transmitted from the optical mode converter (5; 5-1 to 5-3), in accordance with a change in wavelength of the light output from the light source (1; 1-1 to 1-3) or phase of the light output from the light source (1; 1-1 to 1-3), and the actuator is configured to rotate the first planar portion about each of the first and second shafts (7d and 7e). a light source (1; 1-1 to 1-3) capable of changing a wavelength or a phase of a light to be output; an optical mode converter (5; 5-1 to 5-3) connected to an optical waveguide through which the light output from the light source (1; 1-1 to 1-3) transmits, and configured to radiate the light received through the optical waveguide; a mirror arranged around the optical mode converter (5; 5-1 to 5-3), and configured to reflect the light radiated from the optical mode converter (5; 5-1 to 5-3) and then reflected from an object, toward an optical receiver; and an actuator having a first planar portion, a second planar portion, and a third planar portion, wherein the second planar portion has a hole in which the first planar portion is disposed, and the third planar portion has a hole in which the second planar portion is disposed, wherein the third planar portion supports the second planar portion via a first shaft, and is connected to the second planar portion via the first shaft and rotatable about the first shaft, the second planar portion supports the first planar portion via a second shaft substantially perpendicular to the first shaft, and is connected to the first planar portion via the second shaft and rotatable about the second shaft, the first planar portion holds the optical mode converter (5; 5-1 to 5-3) and the mirror, the optical mode converter (5; 5-1 to 5-3) is configured to change a radiation direction of the light to be transmitted from the optical mode converter (5; 5-1 to 5-3), in accordance with a change in wavelength of the light output from the light source (1; 1-1 to 1-3) or phase of the light output from the light source (1; 1-1 to 1-3), and the actuator is configured to rotate the first planar portion about each of the first and second shafts (7d and 7e).