To solve the problem that it is difficult to connect a cap with a lead in a good condition in a cold-cathode discharge lamp.

The cap 11 to be mounted in the discharge lamp has a metallic cap body 12 with an inner diameter large enough to put the glass tube 4 of the discharge lamp therein, a lead connecting unit 13, and a coupling unit 14. The lead connecting unit 13 includes: first and second lead holding units 19, 20 disposed opposite to each other so as to interpose the lead, extending in the axial direction of the cap body, and formed to hold the lead 6; and an intermediate portion 21 connecting these lead holding units to each other, formed opposite to the end side of the glass tube 4, and having an opening 22 to pass the lead 6 therethrough.