A casting mold manufacturing process and apparatus, which sand of the mold contains water-soluble paste of binder. The sand is previously heated in a sand storage tank by micro-wave heating or high frequency. The sand temperature and humidity, and volume of the binder contained in the sand are freely controlled. The preheated sand is blown by a preheated air to supply it to a molding flask placed under the storage tank. The preheated air is controlled in its humidity and warmness.