A lamp device mounted on either side of a bumper of a vehicle includes a lamp casing installed in the bumper; a guide lamp provided at an upper side inside the lamp casing and configured to project light in a predetermined pattern on a road surface to guide a traveling direction of the vehicle; and an illumination lamp provided at a lower side inside the lamp casing and configured to diffuse the light in a traveling direction of the vehicle to illuminate the traveling direction of the vehicle, in which the guide lamp includes a first light source provided at the upper side inside the lamp casing; and a first lens unit provided in front of the first light source and configured to project the light from the first light source in a predetermined pattern on the road surface in order to guide the traveling direction of the vehicle.