The present invention provides a medicinal fluid injector which is connected to a supply tube to which medicinal fluid is supplied and a discharge tube from which medicinal fluid is discharged, so as to store and discharge medicinal fluid. The medicinal fluid injector has: a housing body which forms an outer body； and a reservoir module which is arranged inside the housing body, and stores and discharges medicinal fluid. The housing body has: a grip portion which forms a part of an outer circumferential surface and of which the length in the longitudinal direction is greater than the width in the direction orthogonal to the longitudinal direction； and a pair of button protection arms which are positioned on one end of the housing body so as to be adjacent to the grip portion. The reservoir module is fixed to the housing body within the housing body. The reservoir module has: a reservoir bag which stores and discharges medicinal fluid； and a push button for discharging the medicinal fluid in the reservoir bag by pressing the reservoir bag. The reservoir bag is connected to the supply tube and the discharge tube so as to enable fluid flow. A part of the push button is positioned between the button protection arms, and the push button can move along the central axis of the housing body.La présente invention concerne un injecteur de fluide médicinal qui est relié à un tube d'alimentation auquel un fluide médicinal est apporté et un tube de sortie duquel le fluide médicinal est sorti, de manière à stocker et faire sortir le fluide médicinal. L'injecteur de fluide médicinal comporte : un corps de boîtier qui forme un corps extérieur ； et un module de réservoir qui est agencé à l'intérieur du corps de boîtier, et stocke et fait sortir le fluide médicinal. Le corps de boîtier possède : une partie de préhension qui forme une partie d'une surface circonférentielle extérieure et dont la longueur dans la direction longitudinale est plus grande que la largeur dans la direction o
