1. An optimal technique search method that is performed in a system including an execution device that is initially set in an arbitrary environment so as to derive and perform an operation corresponding to the environment using a neural network and an evaluation device that gives initial settings to the execution device and evaluates content of the operation of the execution device after the operation ends, the evaluation device directing the execution device to perform the operation plural times and deriving the initial settings of the execution device in which a most effective operation is performed from the plurality of derived operation results as an optimal technique, the method comprising: an individual defining step of allowing the evaluation device to make initial settings from a combination of a virtual cell and a molecule required for cell division and transmit the initial settings to the execution device; an execution device operating step of allowing the execution device to create a virtual cell division space based on the initial settings, arrange nodes included in the initial settings, perform a calculation process based on a function to divide the nodes, thereby forming a neural network, input data detected by a sensor provided therein to the neural network after the neural network is formed, thereby deriving output data, operate an operation unit provided therein based on the output data, and transmit the operation result to the evaluation device; and an individual evaluating step of allowing the evaluation device to create individual evaluation for the execution device based on the received operation result, wherein the individual defining step, the execution device operating step, and the individual evaluating step are sequentially performed plural times to derive the most effective operation from the individual evaluation results.