Photometric redshift total χ² distributions for our SMGs with spectroscopic redshifts. We show results based on various sets of spectral models (see text for details): 2T (dotted lines), 6T (dashed-lines), M (full lines). The spectroscopic redshifts are indicated by vertical dashed lines. The source names and the number of degrees of freedom (dof) in the photometric redshift χ² minimization are indicated in each panel. The gray-shaded areas in some of the panels indicate the redshift range ignored for the determination of the best-fit photometric redshift. The photometric redshift provided by the best model (M) and its uncertainty was taken as the minimum χ² value and the 99% confidence interval, respectively, both indicated in each panel by the thick and thin red lines.