To smooth the discharge of a product.

A product discharge outlet structure is provided for a biaxial kneader in which two kneading shafts are inserted through a cylindrical casing in its cylindrical shaft direction, and a material to be processed is introduced from one end upper face of the casing into the casing and a product is discharged from the other end lower face of the casing. The discharge outlet 10 is formed of a nozzle member A fitted into the casing, and the nozzle member A is divided into inner and outer members 10a and 10b with an edge 13 as a boundary, and the divided members are integrated together by fitting protruded line/channels 14a and 14b. A plurality of members 10a of different discharge outlet diameters are provided, and one member 10 of the diameter optimum for the product is used as a replacement. The discharge outlet 10 is formed of a circular section 11 and an oblong section 12, and its boundary is the edge 13. As the discharge outlet is of the circular shape, the adhesion of the product to corners is not generated. As the flow of the product to be discharged along the inner face is shut off by the edge 13, the product is passed through the larger oblong section 12, and the product is hardly in touch with the inner face of the discharge outlet 10 and also the adhesion thereon is controlled. The circular section 11 can be deformed eccentrically to the side of one kneading shaft.