We investigated the current collapse characteristics of the fabricated MIS-HEMT with the SiO2, SiN and high-k gate insulator. TiO2 was employed as the high-k material. We found the significant drain current change in the switching characteristic when the insulator changes. The SiN MIS-HEMT showed good switching characteristic. On the other hand, the MIS-HEMTs with oxide insulator film showed large drain current reduction. We considered that the degradation of the switching characteristic is due to the current collapse.