An ion trap is disclosed comprising: a plurality of electrodes which define a toroidal or annular ion confining volume that extends around a central axis; a first device arranged and adapted to apply one or more DC voltages to said plurality of electrodes in order to generate a DC potential well which acts to confine ions in a radial direction within said toroidal or annular ion confining volume, wherein said radial direction is substantially perpendicular to said central axis; and a control system arranged and adapted to non-mass selectively eject ions from said toroidal or annular ion confining volume. The ion trap enables a large number of ions to be trapped and ejected simultaneously.