A data visualization device includes a module for a specific viewpoint which is selected and a diagram representing the program is generated for modules included in source code. For a module extracted using a module call relationship diagram creation unit, a data analysis unit calculates the relevance of a viewpoint, which is input by a user, by utilizing a module call relationship and a common data usage relationship. The relevance is calculated by multiplying the viewpoint relevance of a viewpoint dependent module serving as the base point and a viewpoint relevance weight in an action determination table and in inter-module path viewpoint relevance weight data. The calculated viewpoint relevance is corrected using a viewpoint relevance correction value in viewpoint relevance determination noise correction threshold data. Final viewpoint relevance is stored into per-module viewpoint relevance determination data and a program diagram in accordance with this viewpoint relevance is created.