Perpendicularly magnetized synthetic antiferromagnetic (p-SAF) structures exhibiting large exchange field (Hex) values have been widely studied for application to spintronic devices. We investigated magnetic properties of p-SAF structures based on Co/Pd multilayers with an ultrathin Ru spacer at various annealing temperatures (Ta). The [Co/Pd]-based p-SAF structures exhibited large Hex values of the order of kOe up to Ta = 350 °C. We clarified that Hex in the p-SAF structures significantly degrades with increasing Ta mainly owing to a marked reduction in exchange coupling energy (Jex). These results demonstrate that [Co/Pd]-based p-SAF structures exhibit sufficiently large Hex values for device applications and that the annealing stability is predominantly determined by Jex.