To provide a method and a device for adjusting tilt of a lens so that the lens does not tilt relative to a lens frame.

Illuminating light from a ring type light source 300 is radiated to a lens to be adjusted 23, an image of reflected light from an optical surface is received by a CCD, and a shifted amount of the image by eccentricity caused when the lens is titled is detected and converted into a tilt angle, then the tilt of the lens is corrected by using an actuator.