A magnetic holding device includes a magnetic base and an object holder. For this purpose, a plate-like member is joined to a top section of the sheet formed in a convex shape, and the spring for generating the negative pressure in the tank is mounted to the same member. The present invention is not only environment-friendly, but also economical as highly expensive equipment is not demanded. min, and a sintering furnace operable to obtain a controlled cooling rate. One embodiment includes a second plurality of particles with at least one phenol functional group attached to the inorganic particle. A control circuit controls the apparatus in such a manner as to place only the memory in a wait state in accordance with the first mode direction, and then stores said input information into the memory in accordance with the second mode direction, at the same time or afterwards, starts the disc driver means.