A robot system includes a manipulator; a work table arranged within a movement extent of the manipulator; an imaging unit for taking a two-dimensional image of the workpieces loaded on the work table; a workpiece supply unit for supplying workpieces onto the work table; and a control system for controlling operations of the manipulator and the imaging unit. The control system includes an imaging control unit for controlling the imaging unit to take the two-dimensional image of the workpieces loaded on the work table, a workpiece detecting unit for detecting a position and a posture of each of the workpieces loaded on the work table by comparing the two-dimensional image taken by the imaging unit with templates stored in advance, and a manipulator control unit for operating the manipulator to perform a work with respect to the workpieces detected by the workpiece detecting unit.