An apparatus for manufacturing fine particles includes a reactor; a first
inlet part including at least one port introducing a reactive gas flow
containing a fine particle source material; a second inlet part including
at least one port introducing a diluting gas flow; a heater exciting the
fine particle source material in the reactive gas flow; a first plate
including through-holes which substantially equalize a flow rate of the
reactive gas flow with respect to a cross section of a flow channel; a
second plate including through-holes which substantially equalize a flow
rate of the diluting gas flow with respect to a cross section of a flow
channel; a gas exhaust port provided in a merging region where the
reactive gas flow passed through the first plate and the diluting gas
flow passed through the second plate are merged; and a collector which
collects fine particles.