To provide a copying device for forming a single-sided to both-sided document using only documents, which eliminates the need for counting or sorting the documents and uses odd-numbered documents from the top as transfer sheets as needed and even-numbered documents as documents, thereby preventing damage to the documents and performing a high speed copying operation.

The copying device includes: a document placement tray; a conveying means which conveys a document from the document placement tray to a transfer paper path; a copying means which conveys the uppermost document on the document placement tray to the transfer sheet path and copies the subsequent uppermost document onto the backside of the document on the transfer sheet path; and a copying control means which continues the operation of the copying means until all the documents on the document placement tray are conveyed.