TMG Asaka Medical Center was established in 1977 as Asakadai Central General Hospital. Since then, the hospital has played a role in reginal medical care centering on Asaka area in Saitama Prefecture. In January 2018, the hospital was renamed to TMG Asaka Medical Center upon relocating to a new facility. At the same time, its emergency service has shifted from a department-based "carpool" system to ER care system. This review reports the effects and issues of the implemented system as well as the impact of COVID-19 since 2020. The results have shown that by establishing the current ER system, the time between receiving a call from EMS to confirming approval to accept a patient had decreased up until 2019. However, in 2020, the time showed an increase due to the prevalence of COVID-19. Since COVID-19 classified as a designated infectious disease, securing hospital beds for infected patients and strengthening infection control measures which include antigen tests allowed the aforementioned time to reduce back. This was a trend observed not only in the emergency department but also among other departments with different physicians. Meanwhile, the emergency department was able to maintain the response time of 1 to 2 minutes-from ambulance arrival to provision of medical attention-throughout the entire period. On the other hand, the response time of other departments, despite being able to reduce it at first, remained prolonged due to the spread of COVID-19. However, the general average of hospital response time was maintained at a similar level before and after the epidemic. This is presumably due the fact that cases requiring primary care by the emergency department had doubled. The results indicate that the ER system is very effective in smoothly accepting emergency patients amid an epidemic such as COVID-19, and that it is important the system continue to be strengthened.