A treatment apparatus of waste water containing oil and fat for grease trap mounted on a grease trap and for decomposing and treating, with an immobilized enzyme, waste oil and fat waste in waste water containing oil and fat within the grease trap, comprising a support plate mounted on the grease trap, an immobilized enzyme holders containing an immobilized enzyme E and through which the waste water containing oil and fat can freely pass, and an agitating means for agitating the waste water containing oil and fat, wherein the immobilized enzyme holders and the agitating means are installed on the support plate.