To provide a non-aqueous electrolyte system electrochemical device having a high energy density and superior in output characteristics of high discharge rate.

The non-aqueous electrolyte system electrochemical device comprises a positive electrode 8 having an active carbon as a main component, a negative electrode 12 having a carbon material as a main component in which lithium is stored beforehand by a chemical method or an electrochemical method in the carbon material capable of storing and releasing lithium ion, and an organic solvent system electrolytic liquid containing electrolyte made of lithium salt. The carbon material of the negative electrode main component is made of two components of an easy graphitized carbon and a hard graphitized carbon and the weight ratio of the hard graphitized carbon material included in the carbon material is 3.3-33.3%.

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