The goal of this study was to explore the age-related decline in the storage and processing components of working memory in dual-tasks (storage trials and processing trials) using eye-tracking. Methods: A total of 39 participants participated in this study. Twenty-two participants were in the younger group (age, 21.45± 3.14 years) and 17 were in the elderly group (age, 66.94 ± 3.58 years). Storage items were based on a word span task. Processing items were based on a sentence comprehension task. These two trials were performed concurrently. Participants completed storage and processing trials while their eye movements were recorded using an eye-tracking device. Performance on this task was indexed (%) by scoring correct items, and proportion of fixation duration (PFD) by recording eye movement data. Results: The results showed that the elderly group demonstrated significantly less accuracy than the younger group on dual-tasks. Also, there was a significant group difference in PFD on processing trials. However, there was no significant group difference in PFD on storage trials. The results suggest that there is a greater age-related decline in processing components in comparison to the storage components of working memory. Conclusion: The results of this study suggest that elderly adults have difficulty in processing components; in particular, the eye movement working memory tasks, due to a reduction in resources such as working memory capacity. The sentence complexity of processing trials did not affect the storage trials, and this suggests that the storage and processing functions of working memory have individual resources.