A peak location calculation device includes a peak value detection block that detects a plurality of candidates for a peak value of intensity of laser light received by an imaging unit consisting of an imaging element formed of a plurality of pixels, and a peak location calculation block that calculates an approximation function that approximates an intensity distribution of the laser light using the plurality of candidates for peak values detected by the peak value detection block. The peak location calculation block calculates the approximation function that minimizes an error between intensity values of the plurality of candidates for the peak value and values of the approximation function.