An image reading apparatus, comprising: an illumination apparatus configured to apply light to an irradiation range, and a reading module, configured to receive light from a reading range, which has the same size as or a size narrower than the irradiation range, and to obtain an image, the illumination apparatus comprising: a first light source module which includes a light-emitting module configured to emit light, the light-emitting module having a line shape, wherein the first light source module includes a light source module in which a plurality of light-emitting devices configured to emit light are arranged in a line; and a first reflection member which includes a first reflection surface configured to reflect the light, which is emitted from the light-emitting module of the first light source module, for illuminating the reading range of the image reading apparatus, wherein the first reflection surface has a cross section that has a zigzag line shape including a plurality of line segments running along a standard ellipse, the standard ellipse being a curve formed by a set of points where a sum of a distance from a first focus and a distance from a second focus is constant, a major axis of the standard ellipse forms a predetermined angle (θ) with an imaging optical axis of the reading module, which is a direction perpendicular to the reading range, in a direction perpendicular to a longitudinal direction of the light-emitting module of the first light source module, the light-emitting module of the first light source module is disposed in a position of the first focus of the standard ellipse, and characterized in that the line segments of the zigzag line shape correspond to tangents to intersection points where the standard ellipse intersects with respective lines drawn from the second focus of the standard ellipse at equal angles. an illumination apparatus configured to apply light to an irradiation range, and a reading module, configured to receive light from a reading range, which has the same size as or a size narrower than the irradiation range, and to obtain an image, the illumination apparatus comprising: a first light source module which includes a light-emitting module configured to emit light, the light-emitting module having a line shape, wherein the first light source module includes a light source module in which a plurality of light-emitting devices configured to emit light are arranged in a line; and a first reflection member which includes a first reflection surface configured to reflect the light, which is emitted from the light-emitting module of the first light source module, for illuminating the reading range of the image reading apparatus, a first light source module which includes a light-emitting module configured to emit light, the light-emitting module having a line shape, wherein the first light source module includes a light source module in which a plurality of light-emitting devices configured to emit light are arranged in a line; and a first reflection member which includes a first reflection surface configured to reflect the light, which is emitted from the light-emitting module of the first light source module, for illuminating the reading range of the image reading apparatus, wherein the first reflection surface has a cross section that has a zigzag line shape including a plurality of line segments running along a standard ellipse, the standard ellipse being a curve formed by a set of points where a sum of a distance from a first focus and a distance from a second focus is constant, a major axis of the standard ellipse forms a predetermined angle (θ) with an imaging optical axis of the reading module, which is a direction perpendicular to the reading range, in a direction perpendicular to a longitudinal direction of the light-emitting module of the first light source module, the light-emitting module of the first light source module is disposed in a position of the first focus of the standard ellipse, and characterized in that the line segments of the zigzag line shape correspond to tangents to intersection points where the standard ellipse intersects with respective lines drawn from the second focus of the standard ellipse at equal angles.