To provide a highly strong silicon nitride tool and its manufacturing method.

For a ceramic chip 1, a wear-resistant hard coating 3 is formed on the surface of a conductive silicon nitride base material 2. The silicon nitride base material 2 is formed by dispersing conductive compound (TiCN, e.g.) into the silicon nitride material in a range of 10-60 volume %. In this way, the specific resistance of the silicon nitride base material 2 is set to be 4.0×10-2-1.0×10-1 Ω.cm. For the hard coating 3, hard material (TiN, e.g.) is formed on the surface of the silicon nitride base material 2 by a physical evaporation method for improving wear resistance, to be 1-5 μm thick.