PURPOSE: To improve the working efficiency by replacing the value of a specific symbol if existing at a connection part with the value of the changing point of a new test pattern or that of a test pattern serving as a base of connection and performing the connection of patterns.

CONSTITUTION: An operator performs a key input operation via a keyboard 24 to designate the test patterns to be connected together. At the same time, the operator inputs the number of steps required for connection of patterns via a designated test pattern. Thus the parts to be connected together are displayed on the screen of a display device 23. Thus the operator decides the new or old value by reference to the screen when the connected part is equal to a space, i.e., a specific symbol showing the contunuation. As a result, plural test patterns already produced are combined together for production of a new test pattern. Thus the new test patterns can be easily produced and edited and therefore no correction is required after production of these patterns. Then the test pattern production efficiency is improved.