A forward osmosis composite hollow fiber membrane module having hollow fiber bundles composed of a plurality of hollow fibers; wherein, the hollow fibers are hollow fibers provided with a separation active layer of a polymer thin film on the inner surface of a microporous hollow fiber supporting membrane, the polymer is a polycondensation product of: at least one or more types of a first monomer selected from polyfunctional amines, and, at least one or more types of a second monomer selected from the group consisting of polyfunctional acid halides and polyfunctional isocyanates, the membrane area of the hollow fiber bundles is 1 m 2 or more, the thickness of the polymer thin film is 0.2 μm to 2 μm, and the coefficient of variation of average thickness of the separation active layer in the radial direction and lengthwise direction of the hollow fiber bundles, as calculated according to a method consisting of measuring the mass of the separation active layer portion in a scanning electron microscope image of a cross-section of the separation active layer in the direction of thickness, is 30% to 60%; the ratio L2/L1 between a length L1 of the interface between the separation active layer and the hollow fiber supporting membrane and a length L2 of the supporting active layer surface in a scanning electron microscope image of a cross-section of the separation active layer in the direction of thickness is 1.2 to 5.0, and the ratio L2/L1 is an average value of nine samples which are obtained by sampling one hollow fiber each from three locations consisting of the center of the module in the radial direction, a location equal to 50% of the radius, and an outermost peripheral portion, and each hollow fiber was then divided into three equal segments in the lengthwise direction. the hollow fibers are hollow fibers provided with a separation active layer of a polymer thin film on the inner surface of a microporous hollow fiber supporting membrane, the polymer is a polycondensation product of: at least one or more types of a first monomer selected from polyfunctional amines, and, at least one or more types of a second monomer selected from the group consisting of polyfunctional acid halides and polyfunctional isocyanates, the membrane area of the hollow fiber bundles is 1 m 2 or more, the thickness of the polymer thin film is 0.2 μm to 2 μm, and the coefficient of variation of average thickness of the separation active layer in the radial direction and lengthwise direction of the hollow fiber bundles, as calculated according to a method consisting of measuring the mass of the separation active layer portion in a scanning electron microscope image of a cross-section of the separation active layer in the direction of thickness, is 30% to 60%; the ratio L2/L1 between a length L1 of the interface between the separation active layer and the hollow fiber supporting membrane and a length L2 of the supporting active layer surface in a scanning electron microscope image of a cross-section of the separation active layer in the direction of thickness is 1.2 to 5.0, and the ratio L2/L1 is an average value of nine samples which are obtained by sampling one hollow fiber each from three locations consisting of the center of the module in the radial direction, a location equal to 50% of the radius, and an outermost peripheral portion, and each hollow fiber was then divided into three equal segments in the lengthwise direction. at least one or more types of a first monomer selected from polyfunctional amines, and, at least one or more types of a second monomer selected from the group consisting of polyfunctional acid halides and polyfunctional isocyanates, the membrane area of the hollow fiber bundles is 1 m 2 or more, the thickness of the polymer thin film is 0.2 μm to 2 μm, and the coefficient of variation of average thickness of the separation active layer in the radial direction and lengthwise direction of the hollow fiber bundles, as calculated according to a method consisting of measuring the mass of the separation active layer portion in a scanning electron microscope image of a cross-section of the separation active layer in the direction of thickness, is 30% to 60%; the ratio L2/L1 between a length L1 of the interface between the separation active layer and the hollow fiber supporting membrane and a length L2 of the supporting active layer surface in a scanning electron microscope image of a cross-section of the separation active layer in the direction of thickness is 1.2 to 5.0, and the ratio L2/L1 is an average value of nine samples which are obtained by sampling one hollow fiber each from three locations consisting of the center of the module in the radial direction, a location equal to 50% of the radius, and an outermost peripheral portion, and each hollow fiber was then divided into three equal segments in the lengthwise direction.