Various metal powders are used in battery electrode materials, depending on the type. Because batteries are used in large quantities in familiar products such as mobile phones, notebook computers, and automobiles, a high level of safety is necessary. Therefore, high purity is demanded in the metal materials used as materials. Quick, simple measurement of the concentration of carbon contained in metal powders is possible by using a Shimadzu total organic carbon (TOC) solid sample system. This article introduces an example of total carbon measurement of lithium cobalt oxide, which is widely used as a positive electrode material of lithium ion batteries.