Method for carburizing tantalum container

A method for carburizing a tantalum container made of tantalum or a tantalum alloy to allow carbon to penetrate the tantalum container, the method comprising the steps of:

• supporting the tantalum container on a plurality of support rods provided in a chamber and setting the tantalum container in the chamber;
• and
• reducing the pressure inside the chamber and heating the interior of the chamber,
• wherein a carbon source is placed in the vicinity of a portion of the tantalum container hard to carburize,
• wherein the tantalum container is formed of a bottom part, a sidewall part, and an opening, and is set in the chamber to face the opening of the tantalum container downward by being supported on the plurality of supporting rods which are in direct contact with the bottom part of the tantalum container from the inside, and
• wherein the plurality of support rods are made of a carbon source.