A process for the cell cultivation of biological cells, except of human embryonic stem cells, on at least one curved boundary surface between at least two different, non-solid cultivation phases in a culture container of a cultivation apparatus, with the steps of: - cultivation phase adjustment so that predetermined cultivation conditions are given, wherein two liquid non-mixable cultivation phases are adjusted in the cultivation apparatus, wherein at least one inner cultivation phase is completely enclosed by an outer cultivation phase, and - cultivation of the biological cells on the at least one boundary surface (30, 32), characterized in that - the cultivation phases are arranged in the culture container, wherein firstly the outer cultivation phase is filled into the culture container and subsequently the inner cultivation phase is injected and the cultivation phase adjustment in the culture container is conducted before or during a deposition of the cells at the at least one boundary surface, - the cultivation phase adjustment comprises an influencing of the geometric properties of the cultivation phases, so that the at least one boundary surface between the cultivation phases gets a predetermined shape, and an arrangement of the cultivation phases relative to each other, so that the boundary surface has a predetermined extension, wherein additive substances, with which the mass density of the cultivation phases is changed and the at least one boundary surface is positioned and shape-stabilized in the cultivation apparatus, are introduced into the cultivation phases in the cultivation apparatus using an injection device, and - the cultivation comprises a differentiation of the biological cells by signal factors and/or differentiation factors, which are included in at least one of the cultivation phases. - cultivation phase adjustment so that predetermined cultivation conditions are given, wherein two liquid non-mixable cultivation phases are adjusted in the cultivation apparatus, wherein at least one inner cultivation phase is completely enclosed by an outer cultivation phase, and - cultivation of the biological cells on the at least one boundary surface (30, 32), - the cultivation phases are arranged in the culture container, wherein firstly the outer cultivation phase is filled into the culture container and subsequently the inner cultivation phase is injected and the cultivation phase adjustment in the culture container is conducted before or during a deposition of the cells at the at least one boundary surface, - the cultivation phase adjustment comprises an influencing of the geometric properties of the cultivation phases, so that the at least one boundary surface between the cultivation phases gets a predetermined shape, and an arrangement of the cultivation phases relative to each other, so that the boundary surface has a predetermined extension, wherein additive substances, with which the mass density of the cultivation phases is changed and the at least one boundary surface is positioned and shape-stabilized in the cultivation apparatus, are introduced into the cultivation phases in the cultivation apparatus using an injection device, and - the cultivation comprises a differentiation of the biological cells by signal factors and/or differentiation factors, which are included in at least one of the cultivation phases.