1. A data classifier for classifying input data using a result of a learning process based on the input data and using a self-organizing map, the classifier comprising: means for forming, through learning, a plurality of self-organizing maps corresponding to a plurality of learning parameters; and means for evaluating each of the plurality of learning-formed self-organizing maps and adjusting the learning parameters based on the result of the evaluation, wherein a learning formation process of a self-organizing map is again performed using the adjusted learning parameters.