PURPOSE: To shorten recognition processing time by trimming branches efficiently while securing a certain degree of a recognition rate in a search system in voice recognition or the like.

CONSTITUTION: In an HMM-LR continuous voice recognizing system composed nearly of an HMM phoneme checking part 1 and an LR purger part 2, a neural network 6 is used as a control function. A recursion factor, a present depth of an LR analytic tree, a difference between the first place hypothetic score at present search time and the first place hypothetic score at right before search time are inputted to the neural network 6, and is learnt so as to output order of a hypothesis of a correct answer. Preferably, in order to prevent useless search by overevaluation, output of this neural network 6 and output by a variable beam search are compared with each other, and the one having a smaller value is selected.