To provide an expanding and drawing method by which a product of complicated shape having a three-dimensional curved surface part in which a plurality of weight lightening hole parts are formed efficiently and also the yield of a base stock is raised.

By performing expand-forming while performing draw-forming of a plate-like base stock after forming a plurality of slit-shaped parts on the plate-like base stock, a product W is obtained by forming the weight lightening hole parts 1, 2, 3 by expanding the slit-shaped parts and simultaneously forming an expanded part Wa including the weight lightening hole parts 1, 2, 3 into a shape of a three-dimensional curved surface. At this time, the shape and size of the slit-shaped part is decided in accordance with the strength and final shape of the product. The amount and direction of expansion at the expand-forming are decided in accordance with the final shapes of the slit-shaped part and the product W.