Leaky-wave antenna, wherein at least one line (110, 111, 210, 211), each having a feed-in point (101, 102, 201, 202), is embedded in an insulating layer (120, 220), and the insulating layer (120, 220) is arranged between an electrically conducting lower layer (130, 230) and an electrically conducting upper layer (140, 240), wherein a multiplicity of antenna elements in the form of openings along the at least one line (110, 111, 210, 211) have been introduced in the upper layer (140, 240), and provided in each case between the at least one line (110, 111, 210, 211) and a respective antenna element (150-153, 155-158, 250-253, 255-258) from the multiplicity of antenna elements is a coupling means, which defines a respective coupling factor which describes the electromagnetic coupling between the at least one line (110, 111, 210, 211) and the respective antenna element (150-153, 155-158, 250-253, 255-258), and, proceeding from the respective feed-in point (101, 102, 201, 202), the coupling factor of the respective antenna element (150-153, 155-158, 250-253, 255-258) increases along the at least one line (110, 111, 210, 211), and the insulating layer (120, 220) has a first insulating ply (121, 221) and a second insulating ply (122, 222), which are preferably formed in each case by a foam material, wherein the lower layer (130, 230) has a first longitudinal overhang and the upper layer (140, 240) has a second longitudinal overhang in a plane longitudinally in relation to the at least one line (110, 111, 210, 211), which longitudinal overhangs (513, 514) project with respect to the conducting ply (115, 215) and/or the first insulating ply (121, 221) and/or the second insulating ply (121, 221), and also an adapter element (550, 560, 570) is inserted between the respective longitudinal overhangs (513, 514). wherein a multiplicity of antenna elements in the form of openings along the at least one line (110, 111, 210, 211) have been introduced in the upper layer (140, 240), and provided in each case between the at least one line (110, 111, 210, 211) and a respective antenna element (150-153, 155-158, 250-253, 255-258) from the multiplicity of antenna elements is a coupling means, which defines a respective coupling factor which describes the electromagnetic coupling between the at least one line (110, 111, 210, 211) and the respective antenna element (150-153, 155-158, 250-253, 255-258), and, proceeding from the respective feed-in point (101, 102, 201, 202), the coupling factor of the respective antenna element (150-153, 155-158, 250-253, 255-258) increases along the at least one line (110, 111, 210, 211), and the insulating layer (120, 220) has a first insulating ply (121, 221) and a second insulating ply (122, 222), which are preferably formed in each case by a foam material, wherein the lower layer (130, 230) has a first longitudinal overhang and the upper layer (140, 240) has a second longitudinal overhang in a plane longitudinally in relation to the at least one line (110, 111, 210, 211), which longitudinal overhangs (513, 514) project with respect to the conducting ply (115, 215) and/or the first insulating ply (121, 221) and/or the second insulating ply (121, 221), and also an adapter element (550, 560, 570) is inserted between the respective longitudinal overhangs (513, 514).