  Shintake monitor is a nanometer-scale electron beam size monitor. It probes a
electron beam by an interference fringe pattern formed by split laser beams.
Minimum measurable beam size by this method is less than 1/10 of laser
wavelength. In ATF2, Shintake monitor will be used for the IP beam size monitor
to measure 37 nm (design) beam size. Development status of the Shintake
monitor, including fringe phase monitoring and stabilization, gamma detector
and collimators, is described. In addition, we discuss the beam size
measurement by Shintake monitor in ILC.
