PURPOSE: To collect and separate acarids from admixtures, by passing the admixtures containing acarids from a coarse filtering face to a fine filtering face by suction with air.

CONSTITUTION: A filtering mechanism which is made by fitting two or more layers of filtering faces 2, 3... to the back of a funnel-like guide 1 and consists of the plural layers of the filtering faces of the first filtering face having 30W70 meshes and the final filtering face having 200W250 meshes is attached to a suction part of a vacuum cleaner. Dusts containing acarids in a room is sucked into the vacuum cleaner, passed through the filtering mechanism, coarse dusts are collected and separated on the first filtering face and the acarids are on the final filtering face. The dusts can be separated from the acarids in such a degree as to observe them directly by a magnifier.