An object is to provide a lamp device which can be used as vehicle use headlight, and can form light distribution pattern capable of suppressing generation of dark grids in the field of view. A lamp device is provided which comprises a light source in which a plurality of light emitting elements are regularly arranged in a plane, and the light emitting elements are distributed along a first direction and along a second direction crossing the first direction in the plane, a projecting optic system capable of forming images of the respective light emitting elements of the light source on an image plane located on an optic axis of light beam emitted from the light source, and an image shifter capable of forming basic image of the plurality of light emitting elements on an image plane, and simultaneously forming first moved image which is formed by moving the basic image along the first direction and along the second direction simultaneously on the image plane.