To reduce man-hours for tests of a program.

A screen generation program analysis unit 103 analyses a screen generation program 101 configured with plural element blocks some of which include variables. An ID output code embedding processing unit 104 and a variable output code embedding processing unit 105 associate each variable with an element block including the variable and store association results in an ID/variable retention unit 10. When a GUI screen as a result of execution of the screen generation program 101 disobeys a rule and a disobedience comparison unit 108 extracts an element block that is a direct cause of the disobedience as a direct-cause element block, a disobedience cause identification unit 109 extracts at least one element block written before the direct-cause element block in the screen generation program 101 among other element blocks associated with a variable common to the direct-cause element block in association information in the ID/variable retention unit 10.