An object of the present invention is to provide a microelectrode capable of recording action potentials of nerve cellsneurons as large-amplitude waveforms and being appropriate for multi-channeling. The electrode 1 of the present invention comprises a conductive linear core material 2, an insulating coating layer 3a with which the outer circumference of the linear core material is coated, and an extending part 3b formed by extending the end part of the coating layer on one tip side of the linear core material beyond the tip in the longitudinal direction of the linear core material, in which a cavity that opens in the extending direction is formed within the extending part.