A computer program for extracting a fetal cardiac potential signal includes: a selecting module configured to select, from among multiple biopotential signals, a biopotential signal containing a high proportion of a maternal cardiac potential signal component an independent component analysis module configured to perform independent component analysis on multiple biopotential signals a periodic signal detection module configured to detect a signal having periodic peaks among a biopotential signal selected by the selecting module and output signals after independent component analysis, as a peak time signal an output signal selecting module configured to acquire, as reference input, a biopotential signal that is selected by the selecting module and detected as a peak time signal and also acquire, as comparison input, a peak time signal among output signals after independent component analysis, so as to select an output signal having peak times different from those of the biopotential signal detected as a peak time signal and a module configured to output a selected output signal.
