In 2011, the Comprehensive Diagnostic Criteria for IgG4-related disease was published in Japan. Organ-specific diagnostic criteria based on organ-specific findings were proposed and published by each of the related societies, and the diagnostic criteria for IgG4-related respiratory disease was published in 2015. Based on the revisions to the comprehensive diagnostic criteria in 2020 and the publication of the Classification Criteria, new diagnostic criteria for IgG4-related respiratory disease are presented. Emphasis has been placed on evaluating specific pathological findings and excluding other respiratory diseases. It is mentioned in the commentary that in cases with imaging findings suggestive of interstitial pneumonia with chronic fibrosis or poor response to steroid therapy, other possible diseases should be considered.