PURPOSE: To obtain the title apparatus for efficiently cleaning a clean tunnel by mounting a filter having the same shape as the cross-sectional shape of the clean tunnel to the front surface of a water carrier in the advancing direction side of said carrier.

CONSTITUTION: The wafer carrier 12 moving through a clean tunnel 11 is provided with a wafer receiving part 15 and a filter 16 made of an antistatic resin and planned so as to have a dimension having an area almost same to that of the clean tunnel 11. When the wafer carrier moves in the tunnel, wind pressure is applied to the filter from the direction of the arrow shown by dotled lines. Therefore, air by this wind pressure in the tunnel is always impinged to the filter and clean air is always formed around the wafer present behind the filter.