To provide a category discrimination apparatus by which a new category is added without revision of a constructed self-organization feature map.

A attack sound testing device 10 is mainly constituted of a condenser microphone 21, a feature map generation section 33, and a category discrimination section 35. The feature map generation section 33 consists of an input layer and a map layer. The map layer consists of two layers, a first M1 and a second layer M2. The feature map generation section 33 fetches teaching data into the first map layer M1 to generate the self-organization feature map F on the first map layer M1, yet, once fetches information on the new category on the second map layer M2 when the new category is added and established after generating the self-organization feature map F and then organizes the new category on the second map layer M2. In this configuration, existing self-organization feature map, namely, the existing criterion is not revised in association with the addition of the category.