Electron beam mask writers have the photomask placed on a stage that moves within a plane, and write the circuit patterns while continually moving the stage. The stage is feedback-controlled using positional information from a precision sensor known as a laser interferometer. Moving the stage that has several tens of kilograms causes mechanical vibrations. There are mainly two types of mechanical vibrations: relatively low frequency vibrations that can be suppressed by mechanical controls, and high frequency vibrations that are difficult to track mechanically. Both of these vibrations need to be controlled in the electron beam mask writers to maintain the pattern position accuracy. To meet these requirements, we have developed and succeeded in applying 1) the highest level ultra-precision stage and optimal mechanical control technology to suppress the relatively low frequency vibrations to a sub-nanometer level, and 2) a beam tracking technology that feeds back signals from the laser interferometer to the electron beam deflection controls to suppress the high frequency vibrations to a sub-nanometer level. By combining these two technologies, the stage position in relation to the electron beam is controlled to be almost stationary to the sub-nanometer level, much like an image stabilizer.