Apparatus for verifying conversion 117 inserts a cord extracting an SQL sentence in a program to handle with Access database system 111 and extracts an SQL sentence at the time of practice automatically. And it is converted into an SQL sentence handled with SQL-SERVER database system 113. And an SQL sentence is carried out with Access database system 111 and SQL-SERVER database system 113, and the result is compared, and the SQL sentence that is mismatched for a result is identified.