An injection system of the present invention comprises a needleless syringe； a transfer passage which connects a first space for accommodating a plurality of injection targets and a second space as a transfer destination of the plurality of injection targets, the transfer passage being installed with the needleless syringe so that an emission port of the needleless syringe is open at inside of the transfer passage； a detecting unit which is capable of detecting transfer through the transfer passage in order for the injection target existing in the first space to go toward the second space； and a control unit which performs emission of the injection objective substance from the emission port of the needleless syringe for every injection target in accordance with the transfer of the injection target, if the transfer of the injection target is detected by the detecting unit. Accordingly, the load exerted on an operator is mitigated as far as possible and the occurrence of various problems concerning the hygiene is suppressed when the injection is performed for a large number of the injection targets such as domestic animals or the like.
