Cleansing method of electric vacuum cleaner

An automatically controlled vacuum cleaner is made to travel along the perimeter of the cleaning region during the operator's designation period by use of a remote controller. During this period the control program stores data for travel distances and 90 deg. turns of the outline path of the cleaning region, then divides the cleaning region into a number of cleaning blocks by using the data to calculate x-y co-ordinates of cleaning blocks. The cleaner is then made to travel to and fro along the sequential cleaning blocks in order to clean them simultaneously with overlapping a predetermined width of each cleaning block.