The invention provides a washing device which is provided with a washing agent feeding container which has no events such as residual washing agent and leakage. The invention comprises a washing agent container (19) which is provided with an opening part at the upper surface and the front surface and a water outlet communicated with an outer drum at the lowermost part of a mortar-type bottom surface; a thin box-type spray-water supplying part arranged at the opening part positioned at the upper surface of the washing agent container; and a drawer-type washing agent feeding part (7) which is arranged between the washing agent container and the spray-water supplying part and can be pulled out or pushed into from the opening of the washing agent container. The bottom surface of the washing agent container comprises a second inclined side (52) arranged from the inner side of the washing agent container to the front side of the washing agent container; a third inclined side (53) connected with the second inclined side and arranged from the front side of the washing agent container to the water outlet; and a rib part (56, 57 and 58) arranged on the second inclined side for controlling the direction and the amount of the water flow.