PURPOSE: To surely and efficiently remove fine particles by slanting, by a specified amount, a straight line of cleaning water's path from its jet point to the hit point which used to be perpendicular to the direction of transporting an object to be cleaned.

CONSTITUTION: An ultrasonic wave is applied and cleaning chemical 2 is jetted out of a cleaning chemical spray unit 3 through a line nozzle system. The straight line of the chemical's path, which used to be perpendicular to the transport direction (X direction) of an object W to be cleaned, is slanted by a specified amount. Thus, the cleaning chemical 2, after it hits the object W, runs on the surface thereof not only in the direction parallel to the transport direction (X direction) of the object but also in the lateral direction. This enables surely and effectively removing fine particles even if there are a lot of steps, composed of lithographed electrical circuit patterns, where they are liable to remain.