An illuminator that emits light from a radially outer portion of the cutting tool toward the cutting tool includes a first light source and a second light source, and a first lens and a second lens. The first lens has a first emission surface including a first outermost portion located farthest and at a first distance from a first center axis including a first light source center of the first light source and perpendicular to the first light source. The second lens has a second emission surface including a second outermost portion located farthest and at a second distance from a second center axis including a second light source center of the second light source and perpendicular to the second light source. A distance between the first center axis and the second center axis is shorter than a sum of the first distance and the second distance.