A seal ring holder for membrane elements which is capable of attaining an increase in the area of membranes packed per element; and a membrane element using the seal ring holder, are provided. The seal ring holder for membrane elements which is disposed at an end part of a spiral wound membrane element to hold a ring seal ring on the outer periphery thereof while allowing a raw liquid to flow into a membrane end part of the membrane element, includes: a first ring part which has a side wall facing an upstream-side membrane end part of the membrane element and is inserted into an end part of a sheathing member of the membrane element; a projecting ring part which has been formed upstream from the first ring part and has side walls respectively on both sides, an edge face of the sheathing member and the downstream-side edge face of the seal ring being fixable respectively to the side walls; a second ring part which is formed upstream from the projecting ring part and to the outer periphery of which the seal ring is to be fitted; and a third ring part which is formed upstream from the second ring part and to which the upstream-side end face of the seal ring is fixable.