A transaction processing device including: a representative key decision portion for deciding a representative key to be any one of the keys of every record of a record group as an object for maintaining consistency in a transaction process; a log compilation portion for updating a subordinate log by adding consistence object information indicating the object for maintaining the consistency to the subordinate log other than a representative log corresponding to the representative key among the logs corresponding to every record of the record group; a log update portion for updating the representative log by writing update information for every record of the record group into the representative log; and a record update portion for updating every record by reflecting the update information written into the representative log in the every record of the record group.