PURPOSE: To provide a neural device for classifying objects at a high speed.

CONSTITUTION: Based on a device with no rear neuron H, any arbitrary sample is taken out of the set of study samples and defined as the object to be classified. Every time when an answer is not correct, the rear neuron H is introduced and connected to an output neuron O for the class of the sample but when the answer is correct, on the other hand, no neuron is added. Concerning a method for introducing the rear neuron H, the neuron is divided into groups by searching whether each introduced neuron is included in the group, in which the neuron already exists, or not and when the neuron is put into the group, it is included but when the neuron is not put into the group, a new group is prepared with this neuron as a center. The border of groups is determined as the function of a distance from the neuron of a creater.