PURPOSE: To enable to execute the accurate decision an the degree of analogy of the comparing character column to the compared character column by comparing the comparing character with the character to be compared which are taken out one character by one character, and by counting the number of the coincidence characters.

CONSTITUTION: A comparing character-string and the number of characters are stored in a register REG-A, and a character-string to be compared and the number of characters are stored in a register REG-B. Each one character is taken out from the REG-A and the REG-B by character extracting parts 11 and 12, the character is supplied to a comparing part 13 and compared, and coincidence/noncoincidence is detected. When the noncoincidence is detected, the character extracting part 12 takes out the character of the next character position as the new character to be compared. On the other hand, when the coincidence is detected, a counter 16 is incremented by one, and the character extracting part 11 takes out the character of the next character position as the comparing character. When the comparison of the final character has been finished, an analogy degree computing part 26 divides the contents of the counter 16 by the number of the characters inside the REG-B, and the degree of analogy is obtained.