Legal basis: Article 18 of the Measures for the Administration of Lawyers' Business Files stipulates that the storage period of lawyers' business files is divided into permanent, long-term and short-term. All lawyers' business files that need to be consulted and used for a long time are classified as permanent custody. Any lawyer's business files that need to be consulted, used and kept as evidence for a long time are classified as long-term custody, and the custody period is 20 to 60 years. All lawyers' business files that need to be consulted and used as evidence in general time are classified as short-term storage, and the storage period is five to fifteen years. As a long-term or short-term custody of the lawyer's business files, the specific storage period is proposed by the archivist and reported to the director of the law firm (legal adviser's office) for decision.