A method for manufacturing the fiber product comprises: a washing step for inserting and washing a semi-manufactured fiber product comprising a fabric having natural fiber; a first drying step for dehydrating and then drying the washed semi-manufactured fiber product; a water repellant solution submerging step for submerging the dried semi-manufactured fiber product so that the water repellant solution penetrates the threads of the fabric and coats the surface of the threads with the water repellant solution; a second drying step for dehydrating and then drying the semi-manufactured product; a thermal setting step for fixing the water repellant solution to the threads; a pliability processing step for washing and rendering the semi-manufactured fiber product pliable; and a product finishing step for dehydrating and drying the semi-manufactured fiber product and producing a finished product.