A sealer holding member for a membrane element is disposed at an end of a
spiral-type membrane element on an outer circumference thereof, and
allows a feed to flow into a membrane end of the membrane element. The
sealer holding member includes a first annular portion, an annular
projection, a second annular portion, and a third annular portion
arranged in this order. The first annular portion is engaged with an
outer-covering member for the membrane element and receives an end of the
membrane element without contacting a side of the membrane element. The
second annular portion receives a sealer on an outside thereof.