Abstract: A drain trap includes an L-shaped inlet tube, a cap, a vertical discharge tube and a garbage blocking member. The inlet tube includes a vertical portion, a horizontal portion having an end integral with the lower end of the vertical portion, an open upper end and an open lower end. The cap closes the open lower end of the inlet tube so that water falling from the open upper end of the inlet tube strikes an inner wall of the cap. The discharge tube has an open upper end and is connected securely to the upper surface of an intermediate section of the horizontal portion of the inlet tube so that the drain trap is generally F-shaped, thereby defining a return area in the horizontal portion of the inlet tube near the cap. The return area permits water that is blocked by the inner wall of the cap to flow upward into the discharge tube. The garbage blocking member is fitted detachably in the intermediate section of the horizontal portion of the inlet tube under the discharge tube.