In the extremely competitive semiconductor market, cost of inventories can considerably boost to bring down manufacturing of costs. Therefore, cost of inventories is a basis for promoting company’s competitive. The purpose of this study focuses on the management of inventory of concepts for diffusion machines of components’ material behavior and property in semiconductor’s factory. In addition, the methodology is how to apply ABC analysis to set up distinct level inventory on different semiconductor’s materials and reduce inaction stock of money. At the same time, comparing the same service, this ABC analysis can reach the minimize inventory situation. This study focuses on ABC analysis and find out the appropriate the level of inventory. Moreover, the target is inaction stock and the minimize inventory of cost to count the proper inventory and compare with ABC analysis control management of results. In one case W company’s inventory of management could reduce inaction stock of cost.