PROBLEM TO BE SOLVED: To provide a fibrous soybean protein in which there are fiber feeling and hardness, resilience is suppressed, and favorable crisp texture, for example tuna like texture is possessed using a soy protein material.SOLUTION: An extrusion object in which a soy protein raw material, calcium, starches, and water are extruded from a die by an extruder under the heating and pressuring is performed by water returning by an acid solution of at most pH5 and/or a solution including a salt, then performed by breaking, and thereby a fibrous soybean protein in which there are fiber feeling and hardness, resilience is suppressed, and favorable crisp texture is possessed can be obtained.
