To provide a tephra identification method for identifying precisely a weathered tephra remained insufficiently with volcanic glass.

This tephra identification method executes a specified mineral extraction step S101 for extracting a specified kind of mineral from volcanic ash discharged by volcanic activity and the tephra that is a pyroclastic material such as a pyroclastic flow, a glass inclusion analytical step S102 for analyzing a glass inclusion included in the mineral extracted by the specified mineral extraction step, and for finding a content ratio of specified components, and a statistical processing step S103 for executing statistical processing as to the content ratio of specified components.