PROBLEM TO BE SOLVED: To attain suitable correlation energy detection and finger (rake) synthesis or the like by simple constitution. SOLUTION: The correlation energy detector for detecting the degree of correlation between a 1st signal series (Ii, Qi) expressed by an I-Q orthogonal component and a 2nd signal series (Hj) is provided with a correlation operation means for finding out each correlation value (Iij, Qij) between the 1st and 2nd signal series and a square sum route operation means for finding out the square sum root √(Iij2+Qij2)} of found correlation values or an absolute value sum operation means for finding out the absolute value sum (|Iij|+|Qij|) of found correlation values. Since the square sum root correlation energy or the absolute value sum correlation energy is adopted as correlation energy instead of conventional square sum correlation energy (Iij2+Qij2), the scale of a circuit can be sharply reduced without reducing maximum value detection accuracy or the like.