An exposure device is provided. The exposure device includes an alignment stage unit, an exposure processing unit and a workpiece moving mechanism. The alignment stage unit includes: an alignment stage that holds a workpiece having workpiece marks thereon; at least one first alignment microscope that detects the workpiece marks of the workpiece; and a first moving mechanism that relatively moves the alignment stage and the first alignment microscope in an 1-axis direction by a width of the workpiece. The exposure processing unit includes: a mask stage that holds a mask having mask marks thereon; a second alignment microscope that detects the mask marks of the mask; and an exposure stage that holds the workpiece. The workpiece moving mechanism moves the workpiece from the alignment stage unit to the exposure processing unit.