PURPOSE: To improve strength and immobilization ratio of a hydration flocculent lipase by interposing a coarse intermediate layer between the upper and lower layers composed of dense layers of a specific density and entangling fiber constituting the respective layers in and between the layers.

CONSTITUTION: A fiber web of a three-layer structure, having 1.5-5.0mm thickness with an intermediate layer composed of a coarse layer, composed of fiber having a larger size with 0.01-0.06g/cm3 apparent density arranged between the upper and lower layers composed of hydrophobic dense layers, having resistance to organic solvents and composed of fiber (e.g. PP) having a fine size with 0.06-0.10g/cm3 apparent density is needle punched and then subjected to surface entangling treatment such as water stream entangling to entangle fiber constituting the respective layers in each layer and between the layers.