A projection optical system projects an image of a first object onto a second object. A first imaging optical system forms a first intermediate image of the first object, and is a refractive optical system. A second imaging optical system forms a second intermediate image of the first object, and includes two mirrors, one of the two being concave. A third imaging optical system forms an image of the first object onto the second object, and includes a lens. The first, second and third imaging optical systems are arranged along an optical path from the first object in this order. The system satisfies the expression 0.80