The raw materials used in the semiconductor assembly process should be inspected to guarantee the quality. The sample of the raw materials used in the incoming inspection are usually discarded after related incoming inspection. This causes huge material waste and cost raise. For recycling the inspected samples and incoming inspection improvement, in this study, we presented an application of DMAIC (define, measure, analyze, improve, control) method. The application improves the incoming inspection method and operation method used in sample extraction stage, incoming inspection stage (appearance, size, characteristic) and repackage stage to avoid damage (scratch, pollution, deformation) and make the samples recycled as raw materials. In the define phase, the discarding levels (50%) of Lead Frame and PCB (Printed Circuit Board), the main raw materials used in the semiconductor assembly, were obtained. The improving level (reduce 80%) were also forecasted. In the measure phase, the inferior levels of raw material samples were obtained. Function Deployment Matrix (FDM) was used to select the extraction method, jig used in incoming inspections and inspector’s movement for repackage as indicators which have affect on quality. In the analyze phase, through the detail analysis to the selected indicators, the plan for modifying the work table’s construction to minimize the inspector’s movement, the plan for improving the storage method to avoid the scratch, pollution and deformation of the raw material samples, the plan for redeveloping the jig used in the incoming inspection to improve the appearance inspection’s operation method, the plan for improving the microscope’s stage were proposed. In the improve phase, the effect of the proposed plans for the improvements above was confirmed. In the control phase, the effective improvements were made as official incoming inspection rules, the inspection room’s environment was also maintained at the same level with assembly line and established a rule of regular check.