The present invention provides a lamp device for a vehicle including a light source and an inner lens through which light which is emitted from the light source passes, in which the inner lens includes a lens unit which diffuses light which is emitted from the light source, and a light guiding unit which protrudes toward the light source from the lens unit to guide the light which is emitted from the light source to the lens unit. Light emitted from the light source is guided by the light guiding unit to be incident onto the lens unit and then is irradiated to be diffused to the outside of the vehicle so that the light distribution performance is improved.