We present high performance normally-off GaN MIS-HEMTs. Devices with n-GaN/i-AlN/n-GaN cap layer, recessed gate and insulated gate structure show high drain current and complete normally-off operation. A maximum drain current and threshold voltage are 800 mA/mm and +3 V, respectively. The off-state breakdown voltage is over 320 V. In addition, a current collapse is very small. These results indicate that the recessed AlGaN/GaN MIS-HEMT with novel triple cap layer could be a promising technology for future device applications.