A raw water channel spacer capable of suppressing formation of a concentration polarization layer in a region in the vicinity of a separation membrane in a raw water channel, and a spiral wound membrane element including the same are provided.A raw water channel spacer 40 is formed by superimposing a first yarn row M and a second yarn row N and it alternately includes:a first mesh structure 52 comprises first rectangular meshes 52a to 52c, which are formed of the yarn rows M, N, that are continuous in the extending direction of the second yarn row N;a second mesh structure 61 comprises meshes that are continuous in the extending direction of the second yarn row N such that an interval in the second yarn row is narrower than an interval of the second yarn row N forming the first mesh structure 52.