A power converting apparatus for an electric vehicle, the power converting apparatus comprising: a power converter that has a plurality of ON/OFF-controlled switching elements (Gu, Gv, Gw, Gx, Gy, Gz) and converts a DC voltage to an AC voltage of an arbitrary frequency to drive an AC rotating machine (1; 25); three opening/closing units (4a, 4b, 4c) for AC blocking, connected between the power converter and the AC rotating machine; a current detector (3a, 3b, 3c) that detects a current flowing between the power converter and the opening/closing units (4a, 4b, 4c) for AC blocking; and a controller that controls ON/OFF of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) and opening/closing of the opening/closing units (4a, 4b, 4c) based on at least the current detected by the current detector (3a, 3b, 3c), characterized in that the controller includes: a fault detector that detects whether any of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) has a short-circuit fault or remains in an ON operation state based on a current value detected by the current detector (3a, 3b, 3c), and outputs a signal indicating a detection result; an ON/OFF controller that when a switching element of a phase that is a first phase has a short-circuit fault or remains in an ON operation state, sets only one of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) that constitutes a second phase other than the first phase to an ON operation state based on the signal from the fault detector and the current value, and outputs a signal for opening the opening/closing unit that is connected to the first phase and the opening/closing unit that is connected to a third phase other than the first phase and the second phase; an opening/closing controller that opens the opening/closing unit connected to the first phase and the opening/closing unit connected to the third phase by the ON/OFF controller based on the signal from the ON/OFF controller, and the opening/closing controller first opens the opening/closing unit connected to the third phase in a first opening operation and then opens the opening/closing unit (4a, 4b, 4c) connected to the first phase in a second opening operation. a power converter that has a plurality of ON/OFF-controlled switching elements (Gu, Gv, Gw, Gx, Gy, Gz) and converts a DC voltage to an AC voltage of an arbitrary frequency to drive an AC rotating machine (1; 25); three opening/closing units (4a, 4b, 4c) for AC blocking, connected between the power converter and the AC rotating machine; a current detector (3a, 3b, 3c) that detects a current flowing between the power converter and the opening/closing units (4a, 4b, 4c) for AC blocking; and a controller that controls ON/OFF of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) and opening/closing of the opening/closing units (4a, 4b, 4c) based on at least the current detected by the current detector (3a, 3b, 3c), characterized in that the controller includes: a fault detector that detects whether any of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) has a short-circuit fault or remains in an ON operation state based on a current value detected by the current detector (3a, 3b, 3c), and outputs a signal indicating a detection result; an ON/OFF controller that when a switching element of a phase that is a first phase has a short-circuit fault or remains in an ON operation state, sets only one of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) that constitutes a second phase other than the first phase to an ON operation state based on the signal from the fault detector and the current value, and outputs a signal for opening the opening/closing unit that is connected to the first phase and the opening/closing unit that is connected to a third phase other than the first phase and the second phase; an opening/closing controller that opens the opening/closing unit connected to the first phase and the opening/closing unit connected to the third phase by the ON/OFF controller based on the signal from the ON/OFF controller, and the opening/closing controller first opens the opening/closing unit connected to the third phase in a first opening operation and then opens the opening/closing unit (4a, 4b, 4c) connected to the first phase in a second opening operation. a fault detector that detects whether any of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) has a short-circuit fault or remains in an ON operation state based on a current value detected by the current detector (3a, 3b, 3c), and outputs a signal indicating a detection result; an ON/OFF controller that when a switching element of a phase that is a first phase has a short-circuit fault or remains in an ON operation state, sets only one of the switching elements (Gu, Gv, Gw, Gx, Gy, Gz) that constitutes a second phase other than the first phase to an ON operation state based on the signal from the fault detector and the current value, and outputs a signal for opening the opening/closing unit that is connected to the first phase and the opening/closing unit that is connected to a third phase other than the first phase and the second phase; an opening/closing controller that opens the opening/closing unit connected to the first phase and the opening/closing unit connected to the third phase by the ON/OFF controller based on the signal from the ON/OFF controller, and the opening/closing controller first opens the opening/closing unit connected to the third phase in a first opening operation and then opens the opening/closing unit (4a, 4b, 4c) connected to the first phase in a second opening operation.