PURPOSE: To provide a feed-forward control type divided neural network which operates at a high speed and a method for constructing the network.

CONSTITUTION: A divided network 10 is composed of a plurality of network layers 1-5 piled up upon another in the form of an upward pyramid. Network layers 1-5 are composed of pluralities of auxiliary networks SN12 and a plurality of nodes is arranged on each auxiliary network SN12, and then, the nodes are constituted in a layered neural network array in which the nodes are completely or partially interconnected. The input and output of each auxiliary network SN12 are 1-bit digital value limited to '0' or '1'. Each auxiliary network SN12 is independent from the other auxiliary networks SN12 in a given network layer 1-5 and, therefore, the network layers 1-5 are divided.