According to one embodiment, there is provided an antireflection member including a first plate part, a second plate part, and a third plate part. The first plate part has a first end and a second end. The second end is arranged at a side opposite to the first end. The second plate part extends from a vicinity of the first end. A first notch part is arranged on the second plate part. The second plate part has an antireflection surface. The third plate part extends from a vicinity of the second end to be opposed to the second plate part A second notch part is arranged at a position corresponding to the first notch part on the third plate part. The third plate part has an antireflection surface directed to the antireflection surface of the second plate part.