Abstract: By heating a kneaded marine paste product with superheated steam in a heating chamber under the conditions that:(A) the superheated steam is blown as the heating source into the heating chamber;(B) the paste product is prevented from being contacted directly by the superheated steam being blown in its initial blown direction into the chamber; and(C) the temperature of the gas phase in the vicinity of the paste product is controlled at less than 100.degree. C.,to coagulate the proteins of the paste product, a paste product without adhesion thereto of water droplets can be obtained, and the drying time after the heat treatment and the energy required for drying can be greatly reduced.