Provided are a base 4 to be inserted into a socket by being rotated around a central axis X of the base, a first body 6 attached to the base 4 so as to be rotatable freely around the central axis X, a second body 8 attached to the first body 6, and a light-emitting module 10 mounted on the second body 8. The second body 8 is attached to the first body 6 so as to be swingable in a direction perpendicular to the central axis X.