1. A cache memory observation device for observing a cache access executed to a cache memory comprising a plurality of cache entries comprising: a cache miss judger for judging a cache miss when the cache access is executed; an entry region judger for judging which of a plurality of entry regions constituted with one or a plurality of cache entries in the cache memory is accessed by each of a plurality of cache accesses using at least a part of an index for selecting an arbitrary cache line in the cache memory; and a cache miss counter for counting number of cache misses judged by the cache miss judger in each entry region which is made to correspond to each cache access by the entry region judger, wherein the cache miss counter comprises: a counter provided with respect to each of divided regions obtained by dividing one of said plurality of entry regions into one or a plurality of pieces; and a counter designator for designating an arbitrary counter using an index from the one or the plurality of counters in accordance with the divided regions, wherein: the cache miss counter counts the number of the cache misses judged by the cache miss judger by each counter designated by the counter designator.