(Background and Purpose) As discussions about the impact of architectural environments on the human brain continue, studies have emerged suggesting that ceiling height influences human emotions and cognitive processes. However, in reality, economic reasons or the intuition of architects and designers often dictate ceiling height decisions. Therefore, there is a need for research that objectively measures and analyzes emotions through EEG(electroencephalography) to provide optimal combinations of floor area and ceiling height that evoke comfort and establish a design rationale for determining ceiling height that aligns with the spatial purpose. (Method) This study involves an experimental investigation using immersive VR with HMD. Participants experienced various combinations of floor area and ceiling height in virtual spaces while their EEG was measured. The experimental scope ranged from a minimum floor area of 3m x 3m to a maximum of 21m x 21m, with ceiling heights starting at 2.4m and reaching a maximum of 7.2m. The experiment period was conducted for 45 days from February 1, 2023, to March 17, 2023. 51 adult participants, aged 20 to 59, residing in the Seoul metropolitan area of South Korea, took part in the experiment. The analysis focused on the relative increase in alpha waves measured in the prefrontal cortex as the indicator. (Results) As for the normality test of the EEG experiment results, about 95.57% of the results of the Shapiro-Wilk test for the difference before and after the experiment satisfied normality. To test the statistical significance of the experiment itself, a parametric method, Paired T-test, was used, and the result was 100% statistically significant. The optimal ceiling height for the floor area was 2.4m for 3x3 and 6x6, 3.6m for 9x9, and the optimal ceiling height increased sharply to 6.0m and 6.6m for 12x12 and 15x15, respectively. The correlation between floor area and ceiling height showed a medium correlation. However, in unrealistically large spaces, a continuous upward relationship in ceiling height could not be confirmed, and the correlation between floor area and ceiling height was also low. (Conclusion) The perceived comfort level associated with ceiling height tends to increase as the floor area expands. However, in extremely spacious environments, this relationship does not persist, and the correlation weakens. Therefore, it can be seen that ceiling height significantly impacts comfort in smaller spaces, but it has less influence in larger areas. Additionally, achieving a relaxed state in unrealistically vast spaces proves challenging, and there are limitations to the ceiling height that can evoke comfort. Future research should explore the correlation between floor area and ceiling height concerning enhanced concentration and compare these findings with the results of this study.