Abstract: In recent years the field of cold molecules has seen much progress, and molecules of ever colder temperatures have been produced. Meanwhile, the techniques of manipulating cold molecules have also been developing and maturing. This paper describes the manipulation of cold molecules with external (electrical, magnetic, or optical) fields, including schemes for their guiding, splitting, reflecting, focusing, and trapping. Experimental results and recent developments are reviewed, ending with a simple conclusion and outlook for possible applications.