A feed-through for applications under high external pressure, comprising a base body; and at least one through-hole (4, 5) extending through said base body; and at least one functional element (6, 7); wherein the at least one functional element (6, 7) is arranged inside the at least one through-hole; wherein the at least one functional element (6, 7) is joined to the base body in fluid-tight manner through an insulating material (11, 12) which surrounds the functional element at least in sections thereof and establishes the fluid-tight join; and comprising pressure compensation means (16, 17, 23 - 29, 30 - 34) for the fluid-tight join of the at least one functional element (6, 7) with the base body, which enhances the pressure resistance of the fluid-tight join of the at least one functional element (6, 7) with the base body against pressure; external meaning that side of the feed-through which faces the respective pressure compensation means; wherein the respective insulating material inside the through-hole extends radially as far as to the edge thereof, wherein R 1 represents this radial extent starting from the longitudinal axis; wherein the pressure compensation means (16, 17, 23 - 29, 30 - 34) is adapted so that a pressure applied under operating conditions, in particular pressure components established by the external pressure perpendicular to the longitudinal extension of the through-hole, are directed to peripheral regions of the material of the base body surrounding the at least one through-hole, and so that this pressure is acting radially on the insulating material, that is perpendicular to a longitudinal axis or axis of symmetry of a through-hole of the feed-through, and wherein the material of the base body is deformable by the pressure, at least in the vicinity of the pressure compensation means (16, 17, 23 - 29, 30 - 34), so that with increasing pressure an increasing clamping effect is exerted on the insulating material (11, 12), which counteracts a widening of the through-hole; and comprising an annular groove (16, 17) in the material of the base body, wherein R 2 represents the radial extent from the longitudinal axis to the inner surface of the annular groove (16, 17); wherein R 2 does not exceed ten times the value of Ri; and/or comprising a protruding portion (30, 34) of the base body, wherein R 2 represents the radial extent from the longitudinal axis to the outer surface of the protruding portion (30, 34), and wherein R 2 does not exceed ten times the value of R 1; and/or comprising openings, preferably blind hole-type openings (23 - 29), in the material of the base body on the side of the base body facing the external pressure, which are preferably arranged symmetrically relative to the through-hole, in particular with their longitudinal axes on a full circle surrounding the through-hole. a base body; and at least one through-hole (4, 5) extending through said base body; and at least one functional element (6, 7); wherein the at least one functional element (6, 7) is arranged inside the at least one through-hole; wherein the at least one functional element (6, 7) is joined to the base body in fluid-tight manner through an insulating material (11, 12) which surrounds the functional element at least in sections thereof and establishes the fluid-tight join; and comprising pressure compensation means (16, 17, 23 - 29, 30 - 34) for the fluid-tight join of the at least one functional element (6, 7) with the base body, which enhances the pressure resistance of the fluid-tight join of the at least one functional element (6, 7) with the base body against pressure; external meaning that side of the feed-through which faces the respective pressure compensation means; wherein the respective insulating material inside the through-hole extends radially as far as to the edge thereof, wherein R 1 represents this radial extent starting from the longitudinal axis; wherein the pressure compensation means (16, 17, 23 - 29, 30 - 34) is adapted so that a pressure applied under operating conditions, in particular pressure components established by the external pressure perpendicular to the longitudinal extension of the through-hole, are directed to peripheral regions of the material of the base body surrounding the at least one through-hole, and so that this pressure is acting radially on the insulating material, that is perpendicular to a longitudinal axis or axis of symmetry of a through-hole of the feed-through, and wherein the material of the base body is deformable by the pressure, at least in the vicinity of the pressure compensation means (16, 17, 23 - 29, 30 - 34), so that with increasing pressure an increasing clamping effect is exerted on the insulating material (11, 12), which counteracts a widening of the through-hole; and comprising an annular groove (16, 17) in the material of the base body, wherein R 2 represents the radial extent from the longitudinal axis to the inner surface of the annular groove (16, 17); wherein R 2 does not exceed ten times the value of Ri; and/or comprising a protruding portion (30, 34) of the base body, wherein R 2 represents the radial extent from the longitudinal axis to the outer surface of the protruding portion (30, 34), and wherein R 2 does not exceed ten times the value of R 1; and/or comprising openings, preferably blind hole-type openings (23 - 29), in the material of the base body on the side of the base body facing the external pressure, which are preferably arranged symmetrically relative to the through-hole, in particular with their longitudinal axes on a full circle surrounding the through-hole.