1. A multi-layered neural network circuit provided with an input layer to which one or plural input vectors are inputted, an intermediate layer having networks in a tree-like structure whose outputs are determined by values of the input vectors, where the number of networks corresponds to the number of the input vectors of the input layer, and an output layer having one or plural output units for integrating all output values of the intermediate layer, said networks comprising a plurality of neurons each of which comprises an output coupled to each output unit of the output layer so as to form a plurality of paths between the intermediate layer and the output layer, the multi-layered neural network further comprising: learning-time memories disposed in each of said paths so as to couple the outputs of the neurons of the intermediate layer with the output units, said learning-time memories operative for storing a learned number representing the number of time that an output value of the intermediate layer which is outputted to a corresponding path is equal to or more than a set value; threshold processing circuits coupled to each of said learning-time memories, said threshold processing circuits having and set threshold value, and operative for outputting a first set value when the learned number which is stored in the corresponding learning-time memory is equal to or more than the threshold and outputting a second set value when the learned number which is stored in the corresponding learning-time memory is less than the threshold; and connection control circuits for connecting a path between the outputs of the neurons of the networks of the intermediate layer and the output units when an output of the corresponding threshold processing circuit is the first set value and disconnecting the path therebetween when the output of the corresponding threshold processing circuits is the second set value, wherein the output units sum the output values of the neurons of the networks of the intermediate layer connected by the connection control circuits.