An object of the present invention is to provide a resin membrane filter having excellent separation accuracy and excellent toughness, and a manufacturing method of the resin membrane filter.
The resin membrane filter of the present invention includes a first main surface, a second main surface, and a plurality of through-holes, in which, in the through-hole, in a case where an average area of an opening portion at a position A which is located at a distance of 10% of a thickness of the resin membrane filter from the first main surface is denoted as Sva and an average area of an opening portion at a position B which is located at a distance of 90% of the thickness of the resin membrane filter from the first main surface is denoted as Svb, 0.8≤Sva/Svb≤1.25, a number ratio Ra of through-holes in which an area of the opening portion at the position A is more than 1.25 times Sva is 3.0% or less, and a number ratio Rb of through-holes in which an area of the opening portion at the position B is more than 1.25 times Svb is 3.0% or less.