A blow mold unit including a blow mold including first and second blow cavity split molds and a plurality of raised bottom molds, first and second pressure receiving plates, a first fixing plate to which the first blow cavity split mold and the first pressure receiving plate are fixed, a second fixing plate to which the second blow cavity split mold and the second pressure receiving plate are fixed, a third fixing plate interposed between the first and second fixing plates and to which the plurality of raised bottom molds are fixed at a first surface thereof, a shaft portion extending vertically from a second surface of the third fixing plate, an elevation guide block fixed to one of the first and second fixing plates and elevation guiding the shaft portion, and an elevating rod extending vertically from the second surface. There is also a blow molding machine which includes the blow mold unit.