It is to provide a process and apparatus for producing soymilk which is obtained by completely deactivating various kinds of enzymes responsible for a grassy smell, while preventing heating unevenness, and inducing appropriate thermal denaturation of protein and a rich flavor, and which can be processed by coagulation into tofu high in water retentivity and elasticity and rich in flavor. [Solving means] The apparatus includes a submerged friction-grinding unit M having a friction-grinding portion in which soybeans are friction-ground together with soybean-grinding water to obtain a raw soybean soup, a heating unit N for heating the raw soybean soup obtained in the submerged friction-grinding unit M, a connecting pipe P2 for connecting the submerged grinding unit M and the heating unit N and a preheating unit Y1 attached to the connecting pipe P2 for preheating the raw soybean soup, whereby the raw soybean soup obtained in the submerged friction-grinding unit M is fed into the heating unit N while being preheated and is then further heated in the heating unit N The heating step by the heating unit N may be divided into multiple stages.