Abstract. Main objective of the LATE (Low Aspect ratio Torus Experiment) device is to realize start-up and formation of spherical tokamak (ST) plasmas by ECH/ECCD alone without Ohmic heating power. Plasma current is started up to 3 kA and maintained for 1 second by injecting microwaves from a magnetron (2.45 GHz, 5 kW). The driven current increases by increasing microwave power and external vertical field for equilibrium. So far, plasma current up to 5 kA has been achieved by injecting microwaves in the range of 20-50 kW from a 2.0 GHz klystron. Magnetic measurement shows that last closed flux surface with a minor radius of a 13 cm and a major radius of R 18 cm (R/a 1.4) is formed. The electron density is higher than the plasma cutoff density, which suggests that ECH/ECCD by mode-converted Bernstein wave takes place.