To enable the manufacturing of a concrete mold material using vibration-free and reverse concrete forming process.

Specified amounts of water 93, a mixing agent, a fluidization stabilizer 98, cement material 99 and aggregate 91 are blended and kneaded in a specified blending vessel 51 (blending/kneading step). Then each of these materials whose blending and kneading are performed by plural batch processes is collected at one spot and is further mixed (mixing/stirring step). A fluid concrete material 9 which is mixed in this mixing/stirring step is injected (forming) into a specified molding frame 2 through an injection device 1 (injection/forming step). Further, the fluid concrete material 9 which is formed in the molding frame 2 is cured and set under specified conditions (setting/curing step). Next, a concrete mold material 8 thus molded is take out of the molding frame 2 (mold parting step). Thus it is possible to form the concrete mold material 8 of specified state by passing it through each of the different steps (finishing step).