[Purpose] Older adults appropriately monitoring their own memory abilities is important for their quality of life. This study examines the relationship between the memory self-efficacy (MSE) factor and the working memory (WM) capacity factor in older adults. [Method] Participants were 278 older adults residing near Nagasaki City, Japan (M = 70.5, SD = 3.6, Max = 79.0, Min = 65.0). MSE Scale (Kawano, 1999) and the Hasegawa Dementia Scale Revised (HDS-R: Kato. et al., 1991) were administered to all participants. The MSE scale consists of 14 items developed by extracting the MSE section from the Metamemory Questionnaire (Dixon et al., 1988), modifying the wording, and adding items. WM span of participants were assessed with Japanese version automated working memory span tasks (Otsuka & Miyatani, 2022). [Results] All the participants scored above the cut-off point for HDS-R, which is 20 points. The results of confirmatory factor analysis confirmed a one-factor structure for both a MSE factor and a WM factor. Analysis of the correlation between the two factors using Structural Equation Modeling revealed a significant positive correlation coefficient of .29. [Consideration] For older adults, the ability to accurately assess their own memory capacity is crucial for utilizing appropriate memory aids and their QOL in daily life. There was a moderate positive factor correlation (.29) between the MSE factor and the WM factor. That is, it was found that the higher the MSE, the higher the WM capacity. This result suggests that older adults partially monitor their own WM capacity.