We must give some form of a command to robots in order to have the robots do a complex task. An initial instruction is required even if they do their tasks autonomously. We therefore need interfaces for the operation and teaching of robots. Natural languages, joysticks, and other pointing devices are currently used for this purpose. These interfaces, however, have difficulty in operating multiple robots simultaneously. We developed a multi-touch interface with a top-down view from a ceiling camera for controlling multiple mobile robots. The user specifies a vector field followed by all robots on the view. This paper describes the user interface and its implementation, and future work of the project.