A robot system, comprising: a manipulator configured to receive a manipulating instruction from an operator; a slave arm configured to perform a series of works comprised of a plurality of processes; an output device; a storage device; and a control device, characterised by the control device being configured, after a given first process, to output to the output device an inquiry of asking which operating mode among three operating modes of an automatic operation mode, a manual operation mode, and a hybrid operation mode the slave arm is to be operated in a second process that is the subsequent process to the first process, and execute first operation processing in which, when selected information for instructing the operating mode selected from the three operating modes is inputted from the manipulator, the selected information is stored in the storage device and a number of times that each operating mode of the three operating modes is selected is stored in a number counter, wherein the selected information relating to the most selected operating mode is set as a first selected information, and second operation processing in which, when the number of times stored in the number counter that the first selected information is stored in the storage device becomes equal to or more than a first threshold number of times, the most selected operating mode is outputted to the output device after the first process is ended, wherein the control device is further configured to execute the second process in the most selected operating mode without inputting further selected information from the manipulator. a manipulator configured to receive a manipulating instruction from an operator; a slave arm configured to perform a series of works comprised of a plurality of processes; an output device; a storage device; and a control device, characterised by the control device being configured, after a given first process, to output to the output device an inquiry of asking which operating mode among three operating modes of an automatic operation mode, a manual operation mode, and a hybrid operation mode the slave arm is to be operated in a second process that is the subsequent process to the first process, and execute first operation processing in which, when selected information for instructing the operating mode selected from the three operating modes is inputted from the manipulator, the selected information is stored in the storage device and a number of times that each operating mode of the three operating modes is selected is stored in a number counter, wherein the selected information relating to the most selected operating mode is set as a first selected information, and second operation processing in which, when the number of times stored in the number counter that the first selected information is stored in the storage device becomes equal to or more than a first threshold number of times, the most selected operating mode is outputted to the output device after the first process is ended, wherein the control device is further configured to execute the second process in the most selected operating mode without inputting further selected information from the manipulator.