An airless dispensing pump container with an airtight nozzle head of a push down type capable of discharging a fixed amount of content is disclosed, in which a vacuum sealing function is enhanced in the whole structure of the present invention, and a content opening and closing plate of a content opening and closing valve member in the construction of a content discharge part of a nozzle head is automatically opened and closed, along with a reliable discharge of the content, and a reverse flow and leakage are prevented by improving a structure of a content pump piston which sucks and transfers the content. When a pump cylinder is slanted at a certain angle along with the content storing container or in case of a content having high viscosity, it is possible to improve the operation errors of the ball valve by providing an inventive structure of the ball valve support installed at a lower side of the stem.