Recently, excavator is used for not only civil engineering but also building demolition, scrap recycling and so on. The reason is thought that it has a general-purpose power supply system and is able to move by itself. In other words, it could be considered a kind of high-powered robot. As a whole, it consists of several modules. Divided roughly by each function, power module such as an engine and pumps, working module such as front structures and hydraulic actuators, traveling module such as crawlers or wheels, operation module such as control levers and pedals. In this time, to gather and carry lots of objectives in scrap yard or somewhere, both a fork grapple and a loader bucket are equipped as a working module. And to carry the objectives quickly to destination, wheeled traveling system is equipped. As a result, we have produced a multi-functional handling machine which has double front attachments and wheels. Then if operators cooperate the modules effectively, they will be able to handle their work more efficiently.