Abstract: An operating device for a swivel working machine so constructed that a fluid pressure motor disposed at the vehicle body is rotated in the forward and reverse directions and stopped by a control valve disposed on the swivel base, and that speed change gears between said motor and travelling means are interlockingly connected to a swing lever disposed at said swivel base. Said lever is constructed so as to be swingingly operated in two directions and its swing operations in one direction and in the other direction may operate said control valve and said speed change gears, respectively.