When washing clothes in a front-loading washer, the lifter affects fabric movement and detergency by lifting up the fabric and then making it fall. In order to clarify the role of the lifter in a front-loading washer, fabric movement, and detergency were examined with or without a lifter. Seven factors are involved in the lifter shape, namely back width (Wb), middle width (Wm), front width (Wf), the ratio between the top and bottom width (c), back height (Hb), front height (Hf), and length (L), which were altered to identify the most effective factors in the lifter shape and how fabric movement and detergency were changed according to lifter shape. When the middle width (Wm), length (L), and gap between the back height (Hb) and the front height (Hf) were increased, fabric movement became more complex and detergency was also increased. A new lifter developed by optimizing these shape factors showed 6.8% higher detergency than a conventional lifter.