Short-arc discharge lamp

A short-arc discharge lamp comprising:

• an arc tube section;
• at least one side tube section connected to at least one end of the arc tube section;
• at least one electrode provided inside the arc tube section;
• and
• at least one lead rod which is provided inside the at least one side tube section and which is connected to the at least one electrode;
• wherein the at least one lead rod has at least one metal body disposed so as to be in contact with the at least one lead rod;
• the at least one side tube section has at least one reduced diameter region;
• the at least one reduced diameter region indicates a region having a smaller diameter than a diameter of a region of the at least one side tube section excluding the at least one reduced diameter region;
• the at least one lead rod is supported by the at least one reduced diameter region via the at least one metal body in a first support section and is supported by the at least one side tube section via a sealing glass that alleviates a difference in thermal expansion between the at least one side tube section and the lead rod in a second support section;
• the at least one lead rod, the at least one metal body, and the at least one reduced diameter area are aligned along a plane perpendicular to the central axis of the at least one side tube;
• and
• at least one coating film is formed on at least one surface of the at least one metal body.