A program conversion device includes converting a program including second loop processing that repeats first processing and determination processing a plurality of times to a program including third loop processing and fourth loop processing; converting the converted program to a first-number-of-times repeating processing that includes second-number-of-times repeating processing of the first loop processing and the second-number-of-times repeating processing of the determination processing; converting the first processing and the determination processing to processing that accesses to memory areas that are different for fourth loop processing and that are continuous in a processing order in the fourth loop processing; and exchanging a processing order of the fourth loop processing and the first loop processing, wherein the third loop processing is the-first-number-of-times repeating processing related to the second loop processing, and the fourth loop processing is the-second-number-of-times repeating processing related to the second loop processing in the third loop processing.