• A. Heo, E.-S. Kim, H.-S. Kim
  Kyungpook National University, Daegu
• R. Ainsworth, S.T. Boogert, G.E. Boorman
  Royal Holloway, University of London, Surrey
• Y. Honda, T. Tauchi, N. Terunuma
  KEK, Ibaraki
• S.H. Kim, Y.J. Park
  PAL, Pohang, Kyungbuk
• A. Lyapin, B. Maiheu, M. Wing
  UCL, London
• J. May, D.J. McCormick, S. Molloy, J. Nelson, T.J. Smith, G.R. White
  SLAC, Menlo Park, California
• S. Shin
  Fermilab, Batavia
• D. Son
  CHEP, Daegu
• D.R. Ward
  University of Cambridge, Cambridge

The ATF2 international collaboration is intending to demonstrate nanometer beam sizes required for the future Linear Colliders. The position of the electron beam focused down at the end of the ATF2 extraction line to a size as small as 35 nm has to be measured with nanometer resolution. For that purpose a special Interaction Point(IP) beam position monitor (BPM) was designed. In this paper we report on the features of the BPM and electronics design providing the required resolution. We also consider the results obtained with BPM triplet which was installed in the ATF beamline and the first data from ATF2 commissioning runs.