Abstract: A spiral wound type membrane module for a water treating apparatus comprising:a water collection pipe having a hollow inside so as to form a water passage in which openings for communicating the hollow inside with the outside are perforated through the pipe walls;a separation membrane and a spacer wound around for several turns while being overlaid with each other to the outer circumferential surface of the water collection pipe, in which the separation membrane and the spacer are wound around such that the spacer is disposed between each of the layers of the separation membrane and, therefore, a channel for raw water to be processed and a channel for processed water after permeated through the separation membrane are alternately laminated between each of layers of the separation membrane; whereinthe spacer constituting the channel for the water to be processed has corrugating ridges extended in the axial direction of the water collection pipe and the corrugating ridges are extended in a zig-zag manner or, in