1. A pattern recognition equipment that matches feature parameters extracted from an input signal against a finite state machine of a tree structure in which a recognition pattern is represented by a path leading from a root to a plurality of leaf nodes to adopt the most likely state transition path reaching the leaf node as a recognition result, comprising: means for calculating a likelihood of the feature parameters for each state of the finite state machine by matching the feature parameters of the input signal against the finite state machine; means for calculating a reward according to a number of reachable leaf nodes from the each state; and a pruning means for comparing aggregate values of an accumulated likelihood and the reward of partial hypotheses in each state at predetermined intervals to exclude partial hypotheses with lower aggregate values from search targets.