Provided is a method of producing a layered article by which a sufficient production speed can be achieved, and preferably, a variation in fusion strength can be suppressed and hence a variation in product quality can be reduced. The method of producing a layered article of the present invention includes fusing at least part of a single-layer body or a laminate including at least one layer including a non-woven fabric of fiber having a fiber diameter of 100 µm or less through ultrasonic welding.