CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi~level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40%. So, we focused how to reduce the consumption of raw slurry In this paper, we presented the pH changes of diluted slurry and pH control as a function of KOH contents. Also, the removal rates of slurry with different dilution ratio were investigated. Finally, the CMP characteristics were discussed as a function of silica (SiO$_2$) abrasive contents.