1. A data processing device comprising: a user interface portion which receives hierarchical data, display data obtained by converting the hierarchical data, and an instruction requesting processing from a user, and presents the display data and a result of the processing to the user, the hierarchical data being data having a hierarchical structure with tuples and lists, each of the tuples being a combination of data of different data types, and each of the lists being a series of data of a same data type; a data managing portion which manages the hierarchical data; a display-data generating portion which generates the display data by converting the hierarchical data; an analysis processing portion which receives the instruction from the user interface portion and implements analysis processing; the user interface portion presenting the hierarchical data in a table format having a row to display names of respective levels and a row to display the names of attributes of the tuples; and the display-data generating portion sampling data of each level of the hierarchical data to extract a part of the hierarchical data by an amount possible to present on the user interface portion, and converting the data extracted by the sampling into the display data.