The present invention resides in a needleless syringe for injecting an injection objective substance into an injection target area of a living body without using any injection needle the needleless syringe comprising a main syringe body an accommodating unit which accommodates the injection objective substance by the aid of a sealing member in an accommodating chamber provided in the main syringe body a pressurizing unit which pressurizes the injection objective substance accommodated in the accommodating unit to move or destroy the sealing member thereby so that the injection objective substance is discharged to outside a flow passage unit which forms a discharge port with respect to the injection target area and which defines a flow passage so that the injection objective substance pressurized by the pressurizing unit is discharged via the discharge port to the injection target area and a preparatory filling unit which fills the flow passage unit with a part of the injection objective substance accommodated in the accommodating chamber by destroying a part of the sealing member before pressurization is performed by the pressurizing unit. Accordingly, it is possible to mitigate the load exerted on the nozzle during the injection and reduce the noise without deteriorating the convenience of a user of the needleless syringe.
