Nebuchadnezzar's Key (ネブカドネザルの鍵, "Nebukadonezaru no Kagi") is an item smuggled out of Bethany Base by Ryoji Kaji during the attempted escape of the Third Angel. The key resembles a miniature human nervous system with the neck attached to the stylized key-like device. "Nebuchadnezzar" is written on the shaft of the key in cuneiform . The portable container holds the key bears other writing in mysterious characters that resemble a simplified version of the symbols on the Angel-sealing hex pillars. The container is heat, pressure, electromagnetic, nuclear resistant and made out of a biological ultra hard lightweight material. The seal is written by SEELE (Rebuild), with a catalog number 000-000-▅▅▅▅, Specimen name and a codebar.
Kaji delivers the item to Gendo Ikari, upon which the following interchange ensues:
- Kaji: Now, as I promised... The stored Lost Number, kept as a backup. The guidepost towards the unification of all souls unto God.
- Gendo: Yes, used to open the door to Human Instrumentality... Nebuchadnezzar's Key.
In Evangelion: 3.0 You Can (Not) Redo, the Key itself is not shown, but its container can be seen multiple times. The first time it is seen is when Kōzō Fuyutsuki informs Gendo Ikari about Kaworu Nagisa showing Shinji Ikari the result of the Near Third Impact, the second time is when Gendo is watching Second Angel Lilith's severed head.
- Nebuchadnezzar was the the name of several Babylonian Kings, one of whom Nebuchadnezzar II invaded Jerusalem after God withdrew his protection of the Jews in response to their sinful idolatry. He subsequently exiled the Jews to Babylon according to the biblical books of Jeremiah and Daniel. While they were in exile Nebuchadnezzar attempted to force the Jews to worship a golden statue of himself as a god however the Jews refused leading to several of them being thrown in a furnace to die, only for them to be saved by an Angel. This story is very much reflected in Evangelion with Gendo using the key to surpass humanity in a failed attempt to attain godhood.
- The key was designed by Ikuto Yamashita
- According to Dan Kanemitsu, they had help from a professor on ancient languages in the writing. 
- ヱヴァンゲリヲン新劇場版：破 全記録全集 p.184
- Evangelion: 2.0 You Can (Not) Advance. Modified from evageeks.org subtitles.
- Evangelion 2.0 Complete Records Collection.
|Technologies and Artifacts|
|Cross-Continuity||Evangelion • Plugsuit • Interface Headset • Synchronization • LCL • Entry Plug • Dummy System • Magi & Magi Achiral • S² Engine • N² Technology • White Moon • Black Moon • Dead Sea Scrolls • Spear of Longinus|
|Neon Genesis Evangelion||Jet Alone • Simulation Bodies • Bakelite • Adam Embryo|
|Rebuild of Evangelion||Beast Mode • DSS Choker • Angel-Sealing Hex Pillar • RS Hopper • AAA Wunder • NHG Gebet • NHG Erlösung • NHG Erbsünde • Advanced Ayanami Series • Shutdown Override Signal Plug • Nebuchadnezzar's Key • Spear of Cassius • Spear of Gaius • Golgotha Object|
|Neon Genesis Evangelion: ANIMA||UX-1 Allegorica • Type-N Robot • Type-3 Prototype Maser Howitzer • Akashima • Su-27 SMN² Platypus II • SEELE Reconnaissance Drone • Q.R. Signum • Orichalcum • Ark • Shroud of Turin|
|Other||Evangelion Weapons • Evangelion Equipment • Evangelion Power Sources • Scientific Terms|