A vehicular lamp comprising: a semiconductor light source that has a plurality of light-emitting chips arranged in a row on a circuit board; a heat sink having a base portion in which the light source is arranged on a front surface; a lens that is arranged in front of the light source and having a flange portion on an outer periphery of a lens portion that radiates light from the light emitting chips as a predetermined light distribution pattern; and a lens holder which has an opening edge portion that receives the flange portion and an outer peripheral portion that extends toward the heat sink side from the opening edge portion, and which mounts the lens to the heat sink, characterized in that the lens portion is arranged to have a width in a horizontal direction that does not exceed twice the row width of the light-emitting chips and is equal to or less than a lateral width in the horizontal direction of the circuit board, an outer shape of the opening edge portion is made substantially identical to the outer shape of the flange portion such that an opening width in the horizontal direction of the opening edge portion is equal to or less than the lateral width in the horizontal direction of the circuit board, and the outer peripheral portion has a shape that widens gradually toward the heat sink side from the opening edge portion, and the lateral width in the horizontal direction of the circuit board is approximately the same as a width of the widened shape of the outer peripheral portion. a semiconductor light source that has a plurality of light-emitting chips arranged in a row on a circuit board; a heat sink having a base portion in which the light source is arranged on a front surface; a lens that is arranged in front of the light source and having a flange portion on an outer periphery of a lens portion that radiates light from the light emitting chips as a predetermined light distribution pattern; and a lens holder which has an opening edge portion that receives the flange portion and an outer peripheral portion that extends toward the heat sink side from the opening edge portion, and which mounts the lens to the heat sink, characterized in that the lens portion is arranged to have a width in a horizontal direction that does not exceed twice the row width of the light-emitting chips and is equal to or less than a lateral width in the horizontal direction of the circuit board, an outer shape of the opening edge portion is made substantially identical to the outer shape of the flange portion such that an opening width in the horizontal direction of the opening edge portion is equal to or less than the lateral width in the horizontal direction of the circuit board, and the lens portion is arranged to have a width in a horizontal direction that does not exceed twice the row width of the light-emitting chips and is equal to or less than a lateral width in the horizontal direction of the circuit board, an outer shape of the opening edge portion is made substantially identical to the outer shape of the flange portion such that an opening width in the horizontal direction of the opening edge portion is equal to or less than the lateral width in the horizontal direction of the circuit board, and the outer peripheral portion has a shape that widens gradually toward the heat sink side from the opening edge portion, and the lateral width in the horizontal direction of the circuit board is approximately the same as a width of the widened shape of the outer peripheral portion.