Abstract: A hollow container of biaxially oriented synthetic resin engaged at the bottom portion thereof with a base cap, in which a bottom portion and a body portion are biaxially oriented, said bottom portion is formed in a regular circular shape of cross section and in a spherical shape swelled downwardly, comprising a base cap having a bottom wall for supporting the lower surface of the bottom portion of said container and a peripheral wall erected upwardly from the peripheral wall of said bottom wall and capable of elastically deforming; and said base cap being watertightly engaged at the inner surface of the peripheral wall thereof with the outer surface of the peripheral wall of the lower end portion of said container and engaged with said container. This container is manufactured by a method of engaging the container with a base cap having no air vent hole. Thus, the air can be readily exhausted in case of press-fitting the bottom of the container into the cap.