A driving support method comprising: detecting a first boundary point group (40a-40f,41a-41f,42a-42f) including boundary points forming a lane boundary line, using a sensor mounted on a vehicle; converting a coordinate system of the first boundary point group (40a-40f,41a-41f,42a-42f) to the same coordinate system as a coordinate system of map data; reading a second boundary point group (32a-32g,33a-33g,35a-35d) including boundary points forming a lane boundary line in the map data from the map data; the method characterized by further comprising determining whether or not a first and a second boundary point in the first boundary point group (40a-40f,41a-41f,42a-42f) are close to each other in a vehicle width direction, depending on whether a distance between the first and the second boundary point is equal to or less than a threshold, to exclude, from boundary points to be matched, the first and the second boundary points that are determined to be close to each other, and/or determining whether or not a third and a fourth boundary point in the second boundary point group (32a-32g,33a-33g,35a-35d) are close to each other in the vehicle width direction, depending on whether a distance between the third and the fourth boundary point is equal to or less than the threshold, to exclude, from boundary points to be matched, the third and the fourth boundary points that are determined to be close to each other; and performing matching (S6,S7) between boundary points in the first boundary point group (40a-40f,41a-41f,42a-42f) that are not excluded from boundary points to be matched and boundary points in the second boundary point group (32a-32g,33a-33g,35a-35d) that are not excluded from boundary points to be matched. detecting a first boundary point group (40a-40f,41a-41f,42a-42f) including boundary points forming a lane boundary line, using a sensor mounted on a vehicle; converting a coordinate system of the first boundary point group (40a-40f,41a-41f,42a-42f) to the same coordinate system as a coordinate system of map data; reading a second boundary point group (32a-32g,33a-33g,35a-35d) including boundary points forming a lane boundary line in the map data from the map data; the method characterized by further comprising determining whether or not a first and a second boundary point in the first boundary point group (40a-40f,41a-41f,42a-42f) are close to each other in a vehicle width direction, depending on whether a distance between the first and the second boundary point is equal to or less than a threshold, to exclude, from boundary points to be matched, the first and the second boundary points that are determined to be close to each other, and/or determining whether or not a third and a fourth boundary point in the second boundary point group (32a-32g,33a-33g,35a-35d) are close to each other in the vehicle width direction, depending on whether a distance between the third and the fourth boundary point is equal to or less than the threshold, to exclude, from boundary points to be matched, the third and the fourth boundary points that are determined to be close to each other; and performing matching (S6,S7) between boundary points in the first boundary point group (40a-40f,41a-41f,42a-42f) that are not excluded from boundary points to be matched and boundary points in the second boundary point group (32a-32g,33a-33g,35a-35d) that are not excluded from boundary points to be matched.