Abstract: A person thrusts a straw into a press-foldable paper package (20) through an insertion section (36) formed in the top thereof, whereupon he or she can pressingly fold the package flat from outside so as to press out the contents for drinking. The top and bottom of the package are bent flat, and triangular projections (21) disposed in the top and projection left and right are bent downward and are weakly adhesively bonded to the lateral surfaces (25) of the package by thermal processing. Disposed below the opposite surfaces (25) of the package are an inverted V-shaped fold (27) in a triangle surface with their bottoms (24) on the bottom side, and vertical folds (29) extending vertically upward from the vertexes (28). The lateral surface (25) of the package can be folded flat by folding the vertical folds (29) and inverted V-shaped folds (27).