Abstract: This invention concerns an endermic injector device (10) for subcutaneous injections without a needle, said device (10) being suitable for injecting under pressure at least one fluid drawn in a measured dose from replaceable phials (15) which are advantageously of a throwaway kind, whereby nozzle means (18), means to aspirate fluid, means to expel fluid and means to provide the required expulsion force are comprised, said device (10) including in cooperation:an aspiration and ejection group (27) consisting of valve means (19) to draw and deliver fluid, a cylindrical chamber (33) to hold fluid together with a removable small piston (34), and safety means with an alignment head (32),a group to control aspiration and expulsion (29) which comprises means for axial withdrawal of said small piston (34), tripping means (36-38) and spring means (52) for the axial forward movement of said small piston (34),means to regulate (60) the pre-loading of said spring means (52) and means (30) to display the quantity of the do