The thin film of N-methylolacrylamide was vapor-deposition-polymerized at the substrata temperature of 210 K, and then was post-polymerized with a rise of the substrate temperature as an annealing treatment. The arrangement change upon the post-polymerization in the annealing treatment was compared with that of the film fabricated by physical vapor deposition (PVD) on the basis of in-situ observations of infrared-reflection absorption spectra. In both cases the changes in the molecular arrangement started at the substrate temperature of 230 K mainly in the position of carbonyl groups. At the same temperature the post-polymerization began also. At an annealing temperature higher than 230 K the post-polymerization accompanied by time orientation change gradually proceeded. In the case of the sim obtained by PVD, the other bonds except C=C showed marked stand-up motion at 240 K. In comparison, in the resulting structure after annealing treatment, the part of -NH-CH2-OH in the PVD film had a more stretched structure than that in the post-polymerized film.