A Fluid injector for an internal combustion engine comprising a valve seat body, wherein the valve seat body extends in axial direction along a central longitudinal axis, wherein the valve seat body comprises a plurality of flow holes through which fluid flows from an inlet portion of the flow holes to an outlet portion of the flow holes when the fluid injector is in operation, and wherein the valve seat body comprises an inner surface which is configured to form a sealing edge between the inner surface and a valve needle of the fluid injector when the fluid injector is in operation, wherein the inner surface comprises: - a first truncated cone surface which is coaxially arranged with respect to the central longitudinal axis and wherein the radius of the first truncated cone surface decreases along a main fluid flow direction, - a second truncated cone surface which is arranged adjacent to the smallest radius of the first truncated cone surface and coaxially with respect to the central longitudinal axis, wherein the radius of the second truncated cone surface decreases along the main fluid flow direction, wherein a first angle between the first truncated cone surface and the central longitudinal axis differs from a second angle between the second truncated cone surface and the central longitudinal axis, and - a spherical surface which is arranged adjacent to the second truncated cone surface and which is coaxially arranged with respect to the longitudinal axis, wherein the spherical surface extends from the smallest radius of the second truncated cone surface to the longitudinal axis, wherein the inlet portion of each flow hole is arranged at the inner surface downstream of the sealing edge, and wherein the first angle between the first truncated cone surface and the central longitudinal axis is larger than the second angle between the second truncated cone surface and the central longitudinal axis, the fluid injector being characterised in that, the valve needle comprises a spherical valve needle ball wherein the sealing edge is formed between the inner surface and the spherical valve needle ball and, wherein the second truncated cone surface is arranged tangentially to the spherical surface. - a first truncated cone surface which is coaxially arranged with respect to the central longitudinal axis and wherein the radius of the first truncated cone surface decreases along a main fluid flow direction, - a second truncated cone surface which is arranged adjacent to the smallest radius of the first truncated cone surface and coaxially with respect to the central longitudinal axis, wherein the radius of the second truncated cone surface decreases along the main fluid flow direction, wherein a first angle between the first truncated cone surface and the central longitudinal axis differs from a second angle between the second truncated cone surface and the central longitudinal axis, and - a spherical surface which is arranged adjacent to the second truncated cone surface and which is coaxially arranged with respect to the longitudinal axis, wherein the spherical surface extends from the smallest radius of the second truncated cone surface to the longitudinal axis, wherein the inlet portion of each flow hole is arranged at the inner surface downstream of the sealing edge, and wherein the first angle between the first truncated cone surface and the central longitudinal axis is larger than the second angle between the second truncated cone surface and the central longitudinal axis, the fluid injector being characterised in that, the valve needle comprises a spherical valve needle ball wherein the sealing edge is formed between the inner surface and the spherical valve needle ball and, wherein the second truncated cone surface is arranged tangentially to the spherical surface.