A blow molding method includes steps of moving a split mold to a parison receiving position where a parison is supplied and receiving a parison, closing the split mold, performing blow molding at a blow molding position, and opening the split mold at a product discharge position and thereby discharging a product. The method further includes steps of: sequentially reciprocating each split mold in trains of split molds provided opposed to each other across the parison receiving position to and from a position opposed to the parison receiving position; and sequentially reciprocating the split mold disposed at the position where the split mold is opposed to the parsion receiving position to and from the parison receiving position for performing blow molding. There is also provided a blow molding apparatus for carrying out this blow molding method.