A container sealing device includes a platform slidable and movable in and out of a casing and having an opening for receiving a container to be sealed. A lever and a support device are slidably attached to the platform, and movable up and down relative to the platform, to support the container. The platform includes a peripheral bulge having a peripheral channel to form an inner peripheral wall which may support an outer flange of the container, and an outer peripheral wall having an orifice for supplying a food preserving agent to the container, and an aperture for vacuuming the container. The support device may be adjusted relative to the lever, to support containers of different heights or depths.