A synchronous-machine starting device for starting a synchronous machine including an armature (ATU, ATV, ATW) for generating a rotating magnetic field and a rotor generating a fixed magnetic field by being supplied with a field current, comprising: an electric power conversion unit configured to convert supplied electric power into AC power for supply to the armature (ATU, ATV, ATW) of said synchronous machine; an AC voltage detection unit configured to detect an AC voltage in the armature (ATU, ATV, ATW) of said synchronous machine; a rotor position detection unit configured to detect a position of said rotor of said synchronous machine based on said AC voltage detected by said AC voltage detection unit; an electric power conversion control unit configured to control said electric power conversion unit based on the position of said rotor detected by said rotor position detection unit; and an abnormality detection unit (10, 20) configured to detect a rotation abnormality of said synchronous machine based on said AC voltage detected by said AC voltage detection unit after supply of said field current to said rotor of said synchronous machine is started wherein said abnormality detection unit (10, 20) is configured to detect the rotation abnormality of said synchronous machine based on the number of times that a level of said AC voltage in the armature (ATU, ATV, ATW) of said synchronous machine attains a predetermined value in the whole or part of a period from a time when supply of said field current to said rotor of said synchronous machine is started to a time when supply of said AC power to the armature (ATU, ATV, ATW) of said synchronous machine by said electric power conversion unit is started. an electric power conversion unit configured to convert supplied electric power into AC power for supply to the armature (ATU, ATV, ATW) of said synchronous machine; an AC voltage detection unit configured to detect an AC voltage in the armature (ATU, ATV, ATW) of said synchronous machine; a rotor position detection unit configured to detect a position of said rotor of said synchronous machine based on said AC voltage detected by said AC voltage detection unit; an electric power conversion control unit configured to control said electric power conversion unit based on the position of said rotor detected by said rotor position detection unit; and an abnormality detection unit (10, 20) configured to detect a rotation abnormality of said synchronous machine based on said AC voltage detected by said AC voltage detection unit after supply of said field current to said rotor of said synchronous machine is started wherein said abnormality detection unit (10, 20) is configured to detect the rotation abnormality of said synchronous machine based on the number of times that a level of said AC voltage in the armature (ATU, ATV, ATW) of said synchronous machine attains a predetermined value in the whole or part of a period from a time when supply of said field current to said rotor of said synchronous machine is started to a time when supply of said AC power to the armature (ATU, ATV, ATW) of said synchronous machine by said electric power conversion unit is started.