PROBLEM TO BE SOLVED: To provide a preparation aid for a syringe capable of easily pushing a plunger. SOLUTION: A case for accommodating a sealed container containing a first preparation material and a holder having a plunger and holding a syringe containing the second preparation material are provided, and the case and the holder are needles in the sealed container. In the piercing direction through which the member is pierced, the sealed container and the syringe are relatively slidably engaged to the communication position where the sealed container and the syringe are communicated by the needle member, and at least one of the holder and the syringe is engaged as an engagement target, and the holder. It is provided with an operating member having a sliding engaging portion for sliding the device to the communication position and a pushing engaging portion for pushing the plunger at the communicating position toward the sealed container side, and between the engaging target and the operating member, to the operating member. A switching structure is provided in which the sliding engaging portion is disengaged from the engagement target by the pushing force of the above, and the pushing engaging portion and the plunger are engaged. [Selection diagram] Fig. 2【課題】プランジャを簡単に押すことができるシリンジ用の調製補助具を提供することを課題とする。【解決手段】第一の調製材料入りの密封容器を収容するケースと、プランジャを有し且つ第二の調製材料入りのシリンジを保持するホルダーとを備え、ケースとホルダーとは、密封容器に針部材を刺通する刺通方向で、針部材により密封容器とシリンジとが連通する連通位置まで相対スライド可能に係合し、ホルダー及びシリンジの少なくとも何れか一方を係合対象として係合し、ホルダーを連通位置にスライドさせるスライド用係合部と、連通位置のプランジャを密封容器側に押す押込用係合部とを有する操作部材を備え、係合対象と操作部材との間に、操作部材への押込力で、スライド用係合部を係合対象との係合を解除し、押込用係合部とプランジャとを係合させる切替構造を設ける。【選択図】図２
