PURPOSE:To obtain an operator station which can effectively use a screen and has the low possibility of misoperation. CONSTITUTION:Based on an auxiliary machine displaying 41 on a plant system screen touched through a touch panel 2, the selection of the auxiliary machine to be operated is performed, the switch displaying to operate the auxiliary machine with the auxiliary machine displaying as an operation object displaying 44 is made into the window displaying, and the operation corresponding to the switch displaying touched through the touch panel 2 is performed to the auxiliary machine. Thus, An operator station in which it is not necessary to provide the switch displaying in correspondence to each auxiliary machine displaying, the screen can be effectively used, the auxiliary machine of the purpose can be surely operated and the possibility of the misoperation is low, can be obtained.
