A robot system comprising: an arm operation control unit configured to control an operation of an arm; and a moving subject detection unit configured to detect whether a moving subject is present in an operation direction region set according to an operation direction of the arm and in an operation range of the arm, the robot system further comprising: a moving subject position range monitoring unit configured to monitor whether the moving subject is present in a moving subject position range set outside an operation range of the arm, whereby the arm operation control unit is configured to operate the arm at a first operation speed when the moving subject detection unit has detected the moving subject; whereby the arm operation control unit is configured to operate the arm at a second operation speed that is different from the first operation speed of the arm when the moving subject detection unit has not detected the moving subject and the moving subject position range monitoring unit has detected the moving subject; whereby the arm operation control unit is configured to operate the arm at the first operation speed when the moving subject detection unit has not detected the moving subject and the moving subject position range monitoring unit has not detected the moving subject. an arm operation control unit configured to control an operation of an arm; and a moving subject detection unit configured to detect whether a moving subject is present in an operation direction region set according to an operation direction of the arm and in an operation range of the arm, the robot system further comprising: a moving subject position range monitoring unit configured to monitor whether the moving subject is present in a moving subject position range set outside an operation range of the arm, whereby the arm operation control unit is configured to operate the arm at a first operation speed when the moving subject detection unit has detected the moving subject; whereby the arm operation control unit is configured to operate the arm at a second operation speed that is different from the first operation speed of the arm when the moving subject detection unit has not detected the moving subject and the moving subject position range monitoring unit has detected the moving subject; whereby the arm operation control unit is configured to operate the arm at the first operation speed when the moving subject detection unit has not detected the moving subject and the moving subject position range monitoring unit has not detected the moving subject. a moving subject position range monitoring unit configured to monitor whether the moving subject is present in a moving subject position range set outside an operation range of the arm, whereby the arm operation control unit is configured to operate the arm at a first operation speed when the moving subject detection unit has detected the moving subject; whereby the arm operation control unit is configured to operate the arm at a second operation speed that is different from the first operation speed of the arm when the moving subject detection unit has not detected the moving subject and the moving subject position range monitoring unit has detected the moving subject; whereby the arm operation control unit is configured to operate the arm at the first operation speed when the moving subject detection unit has not detected the moving subject and the moving subject position range monitoring unit has not detected the moving subject.