Post-COVID-19 ILD is not a rare pathophysiology. Corticosteroid therapy may improve prolonged respiratory symptoms, hypoxemia, and radiographical abnormalities. Coronavirus disease 2019 (COVID-19) is a global problem. Globally, there have been more than 300 million confirmed COVID-19 cases and more than 5 million deaths. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is known to cause severe acute pneumonia, while the clinical courses vary. Post COVID-19 Interstitial Lung Disease (ILD) is considered to be “Long COVID”, which is of great interest because it causes patients’ disabilities, and the mechanisms, clinical course, and treatments have not been well elucidated. Generally, post-COVID-19 ILD is characterized by prolonged radiographical abnormalities such as pulmonary fibrosis (consolidation, irregular reticulation, traction bronchiectasis, etc.). Post infectious organized pneumonia is dominant in post- COVID-19 ILD, although other ILD patterns, such as nonspecific interstitial pneumonia and idiopathic pulmonary fibrosis, have also been reported