PURPOSE: To obtain a data element retrieving method which can improve the processing efficiency and simplify the constitution by finding hash values by making a pair of hash functions to act on a key and indexing the entry of a hash table by making each hash value to act as the index value of a hash table of a two-dimensional constitution.

CONSTITUTION: When a key 'Butter' is inputted, the hash value of each hash function processing section 1 and 2 is found by making the respective hash functions A and B of the sections 1 and 2 to act on the key 'Butter'. Then the entry EN of a hash table 4 is indexed. Since hash values are respectively found from inputted keys by using a pair of hash functions A and B and the entry is referred to by indexing the hash table 4 by using hash values as index values in such way, the probability of occurring a collision between the hash values on the table 4 becomes extremely small. Therefore, a data element retrieving method which can improve the processing efficiency and simplify the constitution can be realized.