A second metal mask (13) having a screen part (13A) provided with
a plurality of parallel, fine slits (13a) arranged at very small
intervals is placed on a base plate (12) serving also as a first metal mask
and provided with a plurality of windows (18) defining regions in which
a material is to be deposited. One end of the second metal mask (13) is
fastened to the base plate (12) by a mask clamp (20) and the other
end of the same is fastened to a slider (23). Resilient force is applied
to the slider (23) by compression coil springs (30). Thus, the screen
part (13A) of the second metal mask (13) is tensioned and thereby
the slits (13a) are stretched straight and are extended at predetermined
pitches. A substrate (17) placed on the second mask (13) is subjected
to a vacuum evaporation process to form fine patterns on the substrate (17)
in a gang-patterning mode.
