1. A processing device of which processing objects are categories contained in a hierarchical structure comprising categories into which products or services are classified and a keyword, comprising: at least one memory operable to store program code; at least one processor operable to read the program code and operate as instructed by the program code, the program code including; acquisition code configured to acquire, for each category contained in the hierarchical structure, a frequency of a name of the category and the keyword co-occurring in a search query given to a search device; identification code configured to identify, when at least a part of a distribution of the acquired frequencies in the hierarchical structure is in conformity with at least one predetermined distribution pattern that is based on a sequence of frequencies within the hierarchical structure, a position in the hierarchical structure of a category of which the name is given by the keyword based on a conformed part of the distribution of the acquired frequencies in the hierarchical structure and the position, in the sequence of frequencies occurring in the distribution pattern, pre-associated with the distribution pattern; the identification code further configured to set a category contained in the hierarchical structure as a category of interest, and identify the each of the categories included in the path from the topmost category of the hierarchical structure to the category of interest and the each of the sate immediately below the categories of interest, and if the distribution of the acquired frequencies along the indentified categories is in conformity with the distribution pattern, identify the position on the path that is pre-associated with the distribution pattern as the position of a category of which the name is given by the keyword; the identification code further configured to identify an immediately upper category by determining frequency of a first keyword and a second keyword co-occurring in a search query in which they are concatenated by at least one boolean operator; creation code configured to create a new category of which the name is given by the keyword at the identified position; and classification code to reclassify existing products and services into immediately below categories of the immediately upper category of the new category in the hierarchal structure.