A blow mold unit comprising: a blow mold including first and second blow cavity split molds to be clamped by bringing parting surfaces thereof into contact with each other, and a plurality of raised bottom molds that define a plurality of raised bottom shapes for a plurality of cavities defined by the first and second blow cavity split molds ; first and second pressure receiving plates that receive mold clamping pressure by bringing parting surfaces thereof into contact with each other; 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; at least one shaft portion extending vertically from a second surface of the third fixing plate opposed to the first surface; an elevation guide block fixed to one of the first and second fixing plates and elevation guiding the shaft portion ; and at least two elevated members extending vertically without penetrating through the elevation guide block , wherein the elevation guide block does not include any penetration holes through which the at least two elevated members are inserted; characterised in that : the at least two elevated members extend vertically from the second surface of the third fixing plate ; and the at least two elevated members are disposed to sandwich the elevation guide block between them. a blow mold including first and second blow cavity split molds to be clamped by bringing parting surfaces thereof into contact with each other, and a plurality of raised bottom molds that define a plurality of raised bottom shapes for a plurality of cavities defined by the first and second blow cavity split molds ; first and second pressure receiving plates that receive mold clamping pressure by bringing parting surfaces thereof into contact with each other; 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; at least one shaft portion extending vertically from a second surface of the third fixing plate opposed to the first surface; an elevation guide block fixed to one of the first and second fixing plates and elevation guiding the shaft portion ; and at least two elevated members extending vertically without penetrating through the elevation guide block , wherein the elevation guide block does not include any penetration holes through which the at least two elevated members are inserted; characterised in that : the at least two elevated members extend vertically from the second surface of the third fixing plate ; and the at least two elevated members are disposed to sandwich the elevation guide block between them. the at least two elevated members extend vertically from the second surface of the third fixing plate ; and the at least two elevated members are disposed to sandwich the elevation guide block between them. <EOS>