An inverter apparatus comprising: an inverter that includes three high-voltage side switching elements (SH, SHU, SHV, SHW) and three low-voltage side switching elements (SL, SLU, SLV, SLW) respectively provided in three phases one by one, and drives a three-phase brushless motor; characterized by an opening and closing control unit that performs controlling so as to cause an electrical angle of the three-phase brushless motor to pass through an angle corresponding to a first combination, to rotate twice by 120° each time to one side in a rotary direction, and to rotate once by 120° to the other side in the rotary direction thereafter, by sequentially closing four combinations (C1 to C4) each of which is formed with one among the three high-voltage side switching elements (SH, SHU, SHV, SHW) and one among the three low-voltage side switching elements (SL, SLU, SLV, SLW); and a detection unit that detects a conduction state of a circuit including the closed high-voltage side switching element (SH, SHU, SHV, SHW) and the closed low-voltage side switching element (SL, SLU, SLV, SLW), wherein all the three high-voltage side switching elements (SH, SHU, SHV, SHW) and the three low-voltage side switching elements (SL, SLU, SLV, SLW) are closed at least once in the four combinations (C1 to C4); the inverter apparatus further comprising: a rotary angle acquisition unit that acquires a rotary angle of a rotor of the three-phase brushless motor, wherein the opening and closing control unit determines the four combinations (C1 to C4) in accordance with the acquired rotary angle of the rotor; the inverter apparatus further comprising: a storage unit that stores a plurality of patterns of the four combinations (C1 to C4), wherein the opening and closing control unit determines the four combinations (C1 to C4) so as to cause a difference between angles of the rotor to be small before and after detection of the conduction state, with reference to the patterns stored in the storage unit. an inverter that includes three high-voltage side switching elements (SH, SHU, SHV, SHW) and three low-voltage side switching elements (SL, SLU, SLV, SLW) respectively provided in three phases one by one, and drives a three-phase brushless motor; characterized by an opening and closing control unit that performs controlling so as to cause an electrical angle of the three-phase brushless motor to pass through an angle corresponding to a first combination, to rotate twice by 120° each time to one side in a rotary direction, and to rotate once by 120° to the other side in the rotary direction thereafter, by sequentially closing four combinations (C1 to C4) each of which is formed with one among the three high-voltage side switching elements (SH, SHU, SHV, SHW) and one among the three low-voltage side switching elements (SL, SLU, SLV, SLW); and a detection unit that detects a conduction state of a circuit including the closed high-voltage side switching element (SH, SHU, SHV, SHW) and the closed low-voltage side switching element (SL, SLU, SLV, SLW), wherein all the three high-voltage side switching elements (SH, SHU, SHV, SHW) and the three low-voltage side switching elements (SL, SLU, SLV, SLW) are closed at least once in the four combinations (C1 to C4); the inverter apparatus further comprising: a rotary angle acquisition unit that acquires a rotary angle of a rotor of the three-phase brushless motor, wherein the opening and closing control unit determines the four combinations (C1 to C4) in accordance with the acquired rotary angle of the rotor; the inverter apparatus further comprising: a storage unit that stores a plurality of patterns of the four combinations (C1 to C4), wherein the opening and closing control unit determines the four combinations (C1 to C4) so as to cause a difference between angles of the rotor to be small before and after detection of the conduction state, with reference to the patterns stored in the storage unit.