PURPOSE: To mold a molded object having an opening having an inverse tapered shape or a cask like shape with good finish accuracy without damaging the edge part of the opening by reducing the internal pressure of a bag-shape soft material at the time of the demolding of a deposited article to deform the protruding part of the soft material so as to contract the diameter thereof.

CONSTITUTION: A bag-shape soft material 13 closed on the leading end side of its protruding part 13A and opened on the opposite side thereof is used to be filled with air if necessary and slip is supplied into the molding space of a mold 11. Since the soft material 13 keeps the inverse tapered shape of the protruding part 13A, a deposited article 17 having an opening 17A having the inverse tapered shape conforming to that of the protruding part 13A is formed. At the time of the demolding of the deposited article 17, the soft material 13 is evecuated from the upper opening thereof by a suction nozzle 18 to deform the protruding part 13A of the soft material 13 so as to contract the diameter thereof and the soft material 13 can be easily pulled out of the through hole 11A of the mold 11.