The invention enhances a cooling effect on a press die for hot press. A lower die includes a first base, a second base mounted on the first base and having an opening in the center, a support table provided in the opening of the second base, and a die portion detachably mounted on the support table and including die pieces. The die portion is divided in die pieces disposed adjoining each other, and cold water pipes are provided in the die pieces respectively. The cold water pipes are bent in a U shape and inserted in the die pieces respectively, and extended downward from the lower ends of the die pieces respectively. The cold water pipes have cooling water injection ends and cooling water ejection ends in a space between the first base and the support table.