The present paper describes a moving permanent magnet linear synchronous motor (MPM LSM) that can move with an acceleration above 100G (=980m/s 2 ), and is also capable of high-precision and high-speed positioning. The MPM LSM consists of a mover including permanent magnets and a double-sided electromagnet stator. It can produce a thrust of 4.56×10 3 N and has a working range wider than 1m. The MPM LSM mover is improved for light weight and is driven using a suitable phase lead for flux weakening. The combination of the improved mover and the suitable phase lead provides motion at an acceleration above 100G and a velocity above 12m/s. The positioning characteristics of the improved MPM LSM are examined using a controller with two suitable phase lead functions. The control system shows a positioning accuracy and a positioning resolution of 500nm, which is similar to the vibration amplitude of the sensor output in open loop. In 300-mm step positioning, the improved MPM LSM shows an acceleration above 660m/s 2 and a velocity above 8.3m/s. It takes less than 101ms to reduce the positioning error to less than 5μm. The temperature rise during positioning is also examined experimentally. Continuous positioning for longer than 30minutes increases the temperature of the MPM LSM, but by less than 6°C.