To provide a lamp for vehicles capable of restraining an increase in the temperature of a semiconductor type light source sufficiently even if a heat radiation fin section provided at a movable section is made lighter.

A headlamp has a swivel mechanism for rocking the application direction of light emitted from an LED 1. A heat sink section 2 for mounting the LED comprises: a heat radiation fin section 22 formed adjacent to the LED; and a rotating shaft 21 of the swivel mechanism sealed with working fluid and connected to the heat radiation fin section. A second heat radiation fin section 61 is formed at a bearing section 6 of the rotating shaft.