Needleless syringe

A needleless syringe for injecting an injection objective substance into an injection target area 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 shutoff wall which forms a substantially gas-tight closed space including the discharge port and the injection target area in a state in which the discharge port is brought in contact with the injection target area.

A needleless syringe for injecting an injection objective substance into an injection target area, the needleless syringe comprising:

• a pressurizing unit configured to pressurize the injection objective substance;
• a discharge port defining a flow passage of the pressurized injection objective substance to be discharged to the injection target area;
• and
• a shutoff wall which forms a substantially gas-tight closed space including the discharge port and the injection target area in a state in which the discharge port is brought in contact with the injection target area.