Lamp unit and power supply attachment

A lamp unit comprising:

• a light emitting element;
• a reflector that reflects light emitted from the light emitting element toward a unit front;
• a heat sink that supports the light emitting element and the reflector;
• and
• a power supply attachment for supplying power to the light emitting element that is attached to the heat sink,
• wherein
• the reflector is fastened to the heat sink at two left and right positions of the reflector,
• the power supply attachment includes an opening formed so as to surround the light emitting element, and a connector portion that accommodates a terminal portion electrically connected to an external power source,
• the connector portion of the power supply attachment is positioned inside two left and right fastening positions of the reflector, and
• the two left and right fastening positions of the reflector are set to positions overlapping the opening of the power supply attachment with respect to a unit front-rear direction.