In a method for cleaning the foreign materials filtering, foreign materials collected in a foreign materials filtering space can be easily removed under a filter unit is separated from or is mounted at a filter cover unit. As a result, can be solved the conventional problems that a net filter has to be kept inside out at the time of a cleaning process to cause a user's hands to become dirty, and there is a difficulty in removing foreign materials from the net filter due to a fibrous characteristic of the net filter. Accordingly, a cleaning operation for the foreign materials filtering apparatus can be facilitated.