A fluid dispenser device comprising a body (1), a fluid reservoir (3) containing two half-doses of fluid, a dispensing orifice (30), and dispensing means (5, 6, 7, 8, 9) for dispensing a respective half-dose of fluid each time the dispensing means are actuated, said dispensing means being implemented so that each of the half-doses of fluid can be dispensed during a respective one of two successive occasions on which the dispensing means are actuated, it being possible to actuate the dispensing means on said successive occasions by the user of the device using a single hand, the dispenser device further comprising energy accumulation means (50, 51, 55) adapted to accumulate energy in the hand of the user, said energy being released suddenly from a predetermined force exerted by the hand of the user on said dispensing means, thereby guaranteeing that each of the half-doses is dispensed in full, said fluid dispenser device being characterized in that the dispensing means comprise: a dispensing member (8), such as a piston, mounted to slide in said reservoir (3) for dispensing the fluid; an actuating element (5) mounted to move between a rest position and an actuating position, and on which the user exerts an actuating force to move said dispensing member (8) inside said reservoir (3), said actuating element being mounted to move in a direction substantially transverse to the direction in which the dispensing member (8) moves; and dose-splitting means (7, 12) for dispensing a half-dose of fluid each time the dispensing means are actuated.