Method for manufacture of filtering core

A filtration film element for a film separator used in a water treatment apparatus, and a method of manufacturing this kind of filtration film elements. A filtration film element is formed by bonding an organic filtration film, which consists of a plate type support member of a nonwoven cloth both surfaces of which are coated with film members, on the surface of a filtration plate. A part of the film members with which the support member is coated is melted to expose the relative part of the support member. The exposed part of this support member and the corresponding part of the filtration plate are then fixed to each other by bonding.