Abstract: An ion confinement, i.e., trap, apparatus comprises electrically conductive members, including concentric, coplanar rings or parallel sheets separated by dielectric spacers disposed on the outer edges of the sheets, each of the sheets having a circular hole, the circular holes being symmetrically aligned substantially along a common axis. The trap apparatus further has means for applying an RF potential to the conductive members, such that the resulting electric field being generated in the space defined by the conductive members has a characteristic of a substantially quadrupole field. A charged particle, being injected into the space, is confined in the field, maintaining a dynamic equilibrium condition.