A 640x480 pixel field emitter array (FEA) image sensor with a high-gain avalanche rushing amorphous photoconductor (HARP) target was fabricated and tested as a step toward the development of ultrahigh-sensitivity compact image sensors for high-definition television cameras. For this sensor, an active-matrix Spindt-type FEA integrated with scanning circuits and a magnetic electron focusing system were designed, and a 15-mu m-thick-HARP target was used. The experimental results revealed that the prototype sensor had enough resolution for its pixel number and high sensitivity due to the electrons emitted from the active-matrix FEA being focused onto the HARP target.