A dual-chamber type prefilled syringe comprises a cylindrical member made of glass or the like, an interior area of which is partitioned into a front chamber and a rear chamber by a plurality of plug members. The respective chambers preliminarily and independently contain injection medicine and its dissolving solution or the like.An end plug member (13) is inserted and fitted into a side of a base end portion (4) of the cylindrical member (2). A middle plug member (14) is arranged between a front end portion (3) and the end plug member (13). The cylindrical member (2) has an inner surface between the front end portion (3) and the end plug member (14), projected outwards to provide a bypass (20) shaped like a groove. The bypass (20) has a length in a direction of an axis (19) of the cylindrical member (2), which is made longer than the middle plug member (14). The bypass (20) has an inner surface the end surface of which is situated on a side of an inlet (21) formed on the side of the base end portion (4) and uprises outwards by an angle (θ) which is formed larger than 45 degrees with respect to the axis (19) of the cylindrical member (2).It is possible to reduce a phenomenon in which the dissolving solution or the like liquid agent splashes out of the bypass when communicating the front chamber with the rear chamber, which results in the possibility of effectively preventing the leakage of the liquid agent from a front end of an injection needle.
