An injection volume regulating device for liquid medicine, including a fixing member, a regulating member, a passage recess-sealing member, an outflow hole-sealing member, and a fastening member. The fixing member includes an inlet connected to a medicine supply hose, an inflow hole to deliver the medicine to the regulating device, an outflow hole to be supplied with the medicine from the regulating member, an outlet to discharge the medicine to the hose to allow the medicine to be supplied to a needle, and an insertion hole to be equipped with the fastening member. The regulating member includes a passage recess that is connected to the inflow hole, a liquid medicine-delivering groove connected to the outflow hole, and an insertion hole to be equipped with the fastening member. The passage recess-sealing member communicates the inflow hole with the passage recess. The fastening member fastens the fixing member to the regulating member.