An apparatus is disclosed for the production of frozen ice-cream mass with solid ingredients, which in the finished ice-cream mass will appear substantially as inclusions which distinguish themselves by flavour, appearance and/or consistency from the surrounding homogenous ice-cream mass. The apparatus comprises a first through-flow freezer for cooling of a continuous flow of mass, and a second through-flow freezer for further cooling of the continuous flow of mass, where a mixing-in arrangement for the mixing of solid ingredients into the continuous flow of mass is inserted between the through-flow freezer and the second through-flow freezer. It is hereby achieved that the mixing-in of the solid ingredients takes place in the frozen ice-cream mass when this has a temperature between -3.degree. C. and -7.degree. C. at which the viscosity of the mass is low. In order to achieve this uniform distribution of the solid ingredients, it is an advantage that the second through-flow freezer comprises a freezing cylinder and a conveyor screw which comprises a plurality of screw flights, at least two of which extend over the inlet part of the longitudinal extent of the conveyor screw, and where the outer edges of the two screw flights extend at different radial distance from the longitudinal axis. There is hereby achieved a better induction to the second through-flow freezer, and the inlet pressure can be reduced, typically to 4-6 bar.