The present invention relates to a pumping device of a fluid vessel that discharges a predetermined amount of contents, and more particularly, to a push button of a pumping device of a fluid vessel including a push panel having a push part capable of being pushed by applying force on an upper front surface; and a connection rod formed at a lower end of the push panel and including a pump pressing part pushed as the push part is pushed and a rotation part serving as a central axis of an operation of the pump pressing part as the push part is pushed, a distance between the push part and the rotation part being longer than that between the pump pressing part and the rotation part, and a pumping device of a fluid vessel using the same.