Robot apparatus has a robot 1, a controller 2 for controlling the aforementioned robot 1 to perform working, and a plurality of external axis devices 4, 5 and 6 to be controlled by the aforementioned controller 2. The aforementioned external axis devices 4, 5 and 6 are provided with power switches 4b, 5b and 6b to be operated by an operator 9 so as to turn on/off power supplies thereto, and power supply circuits 4a, 5a and 6a to be operated from the aforementioned controller 2 so as to turn on/off the power supplies. Priority is given to operation using the aforementioned power switches 4b, 5b and 6b over operation from the aforementioned controller 2 as to tuning off the power supplies to the external axis devices 4, 5 and 6.