The ANEPE instrument on Interball Auroral Probe is identical to that on the spacecraft Intercosmos-Bulgaria-1300. It consists of three sets of cylindrical electrostatic analyzers (ESA); each set had three ESAs, one to measure protons and two to measure electrons. The angular field of view for each individual analyzer was 7 degrees X 24 degrees. One set viewed out along the spacecraft Z-axis and the other two along perpendicular axes in the spacecraft X_Y plane at azimuthal angles of 50 and 140 deg. The energy per charge range from 0.2 to 15 keV/q could be covered by up to 16 channels/s and the energy rsolution adjusted to 0.1, 0.2 or 0.3. The flux range was 1.E4 to 1.E9 particles/(sq cm-sr-keV-s).