PROBLEM TO BE SOLVED: To make it possible to create waste liquid as an edible material, and increase an amount of protein.SOLUTION: A treatment method of oil palm by-products comprises: a separation process (1) in which a fruit is taken out from a fruit bunch of oil palm, pulp fiber residues and waste liquid which are by-produced in squeezing the fruit and extracting the crude palm oil are used, a palm kernel meal which is by-produced in extracting palm kernel oil from a seed separated when squeezing the fruit is used, and skin residues are removed as much as possible from the squeezed residues of the fruit to obtain pulp fiber residues； a residual oil extraction process (2) of performing squeezing treatment to a by-product having an empty fruit bunch as a main ingredient to extract residual oil of the crude palm oil； a concentration process (3) of concentrating waste liquid； a mixing process (4) of mixing the pulp fiber residues and the palm kernel meal into concentrated liquid of waste liquid to create a mixture； and a drying process (5) of drying the mixture to create an edible material.SELECTED DRAWING: Figure 2
