A transfer robot system with a manipulator. The transfer robot system includes a track extending between a first position at which a container containing a workpiece is placed and a second position to which the workpiece in the container is fed; a manipulator movable along the track and capable of holding the container and the workpiece; a temporary container-depository movable along the track synchronously with the manipulator, the container taken out from the first position by the manipulator being temporarily put thereon; a workpiece detecting section for detecting the position and the orientation of the workpiece, contained in the container put on the temporary container-depository, during a period when the manipulator and the temporary container-depository move along the track synchronously with each other; and a transfer control section for controlling the manipulator, based on a detection result in the workpiece detecting section, to make the manipulator pick out the workpiece from the container put on the temporary container-depository and feed the workpiece picked from the container to the second position.