A robot system including robot control devices, a network, and a mode changing device which switches between an automatic operation mode and teaching mode. In the state where the mode changing device selects the automatic operation mode, drive power is supplied to all of the robots regardless of the state of the enable device. In the state where the mode changing device selects the teaching mode, when the enable device does not permit operation of at least two robots, the drive power of all of the robots is cut.