An automatic milking arrangement and method in which apparatus is taken to a milking location M, where an animal to be milked is located, by a freely-moveable self-driven device (1) provided with a remote controlled guidance system to move and steer the device automatically. The apparatus comprises a milking unit (71), which includes milking equipment with one or more teat cups (13), and which is automatically demountable from the self-driven device (1) at the milking location. A robot arm (11) carried by the self-driven can serve as a connecting means for connecting the teat cup(s) to the udder of the animal and it may also serve to unload the milking unit (71) from the self-driven device. The milking unit is capable of milking the animal after connection of the teat cup(s) without requiring the self-driven device or robot arm to be present or nearby so that they can leave the milking location and be used to perform other tasks.