To enable even non-skilled workers to finish armholes well.

A jacket J is hung inside out on a hanger 2 and a press buck 5 is inserted into an armhole Ja. Then the shape of the armhole Ja is smoothed so as for a mold part Jb to be sucked by the press buck 5 under a negative pressure, which keeps the shape of the part Jb. And the part Jb is clamped between the press buck 5 and a heated iron 7 by a press device 6 so that the edge of the armhole Ja is molded.