A head part module of a discharge pump for a discharge container, in which the head part of the pump mechanism can be readily varied. A head part module of a discharge pump includes a mounting cap having a link cylinder upwardly extending via an inward flange from an upper end of a mounting cylinder: a cover ring having a top plate with a through hole in the middle part thereof, an outer wall hanging from an outer circumference of the top plate, a first fitting strip and a second fitting strip circumferentially provided on the rear face of the top plate, a top part of the link cylinder, being loosely fitted into the second fitting strip; and a push down head having an outer cylinder hanging from an outer circumference of a top plate a first communication tube hanging from a rear face of the top plate above the through hole and a nozzle forwardly projecting from the outer cylinder, the outer cylinder being fitted onto an outer face of the outer wall.