A hand-operated pump that can be mounted in a cosmetic container is provided. A compression spring that provides restoring force during pumping is provided outside a housing such that it is possible to prevent contents from being contaminated and to easily pump highly viscous contents. Also, since the compression spring is stably fixed to a shaft in a state where the button is separated, it is possible to easily assemble the pump, to easily partialize parts (to modularize parts), and to prevent the pump from malfunctioning even if the button drifts away while in use. Also, since an introducing hole in the lower end of the housing is opened and closed by an opening and closing member of a specific shape, it is possible to obtain high sealing force and pumping force during pumping.