Separation membrane element

Provided is a separation membrane element, wherein it is possible to increase the amount of fluid permeating per unit time and to improve stability performance. Specifically provided is a separation membrane element configured from a separation function layer on the surface, a separation membrane having a non-woven fabric functioning as a base material on the rear surface of the separation membrane, and a permeation-side passage material disposed on the rear surface side of said base material, wherein the permeation-side passage material is formed from a different material from the separation membrane, and the ratio of the projection area of the permeation-side passage material relative to the separation membrane is 0.03 to 0.80.