In this microlens array, unitary microlens arrays are respectively stacked onto an upper surface and lower surface of a glass plate, and each of the unitary microlens arrays is supported by an upper plate and a lower plate. Marks for alignment are formed on each of the unitary microlens arrays and on the glass plate, and the unitary microlens arrays and the glass plate are stacked onto each other aligned by these marks. This makes it possible to prevent ununiform exposure in scanning exposure using a plurality of microlens arrays.