There are 14 books in 新世紀エヴァンゲリオン / Neon Genesis Evangelion Series.
Originally published in Japanese as 新世紀エヴァンゲリオン (Shinseiki Evangelion). This is the original volume division used by most editions of this series.
Other series related to 新世紀エヴァンゲリオン / Neon Genesis Evangelion Series are Neon Genesis Evangelion - 28 volume edition and 新世紀エヴァンゲリオン 愛蔵版 [Shin Seiki Evangelion aizōban] .