A method for designing a primer used for a polymerase chain reaction, the method comprising: a target region selection step of selecting a target region to be amplified through the polymerase chain reaction, from regions on a genome; a primer candidate base sequence generation step of generating at least one base sequence of a primer candidate for amplifying the target region based on each base sequence in vicinity regions at both ends of the target region on the genome; a local alignment step of obtaining a local alignment score by performing pairwise local alignment on the base sequence of the primer candidate under a condition that a partial sequence to be subjected to comparison includes the 3' terminal of the base sequence of the primer candidate; a first stage selection step of performing first stage selection of the base sequence of the primer candidate based on the local alignment score obtained in the local alignment step; a global alignment step of obtaining a global alignment score by performing pairwise global alignment on a base sequence which is of an up to three base length and includes the 3' terminal of the base sequence of the primer candidate; a second stage selection step of performing second stage selection of a base sequence of the primer candidate based on the global alignment score obtained in the global alignment step; and a primer employment step of employing the base sequence of the primer candidate which has been selected in both of the first stage selection step and the second stage selection step as a base sequence of a primer for amplifying the target region, wherein both steps of the local alignment step and the first stage selection step are performed before or after both steps of the global alignment step and the second stage selection step, or performed in parallel with both steps of the global alignment step and the second stage selection step. a target region selection step of selecting a target region to be amplified through the polymerase chain reaction, from regions on a genome; a primer candidate base sequence generation step of generating at least one base sequence of a primer candidate for amplifying the target region based on each base sequence in vicinity regions at both ends of the target region on the genome; a local alignment step of obtaining a local alignment score by performing pairwise local alignment on the base sequence of the primer candidate under a condition that a partial sequence to be subjected to comparison includes the 3' terminal of the base sequence of the primer candidate; a first stage selection step of performing first stage selection of the base sequence of the primer candidate based on the local alignment score obtained in the local alignment step; a global alignment step of obtaining a global alignment score by performing pairwise global alignment on a base sequence which is of an up to three base length and includes the 3' terminal of the base sequence of the primer candidate; a second stage selection step of performing second stage selection of a base sequence of the primer candidate based on the global alignment score obtained in the global alignment step; and a primer employment step of employing the base sequence of the primer candidate which has been selected in both of the first stage selection step and the second stage selection step as a base sequence of a primer for amplifying the target region, wherein both steps of the local alignment step and the first stage selection step are performed before or after both steps of the global alignment step and the second stage selection step, or performed in parallel with both steps of the global alignment step and the second stage selection step. <EOS>