This paper proposes a detection technology of the switch open-circuit fault in the matrix converter. Matrix converter is classified into two types, direct matrix converter (DMC) and indirect matrix converter (IMC), and this paper will review a detection of the open-circuit fault in the IMC. The proposed fault detection method judges fault state and distinguish a location of switch fault after compared with patterns created based on measured current for each phase. It verifies the validity the proposed fault diagnostic technology of a switch open-circuit fault through the simulation.