A syringe pump is equipped with mechanism for easy handling of syringes of different sizes. The syringe pump is equipped with a plunger holding device. The plunger holding device includes a retainer housing with two retainer bars. The plunger holding device also includes two handles and a sensing plate. When two handles move toward each other, the retainer housing moves forward and two retainer bars moves away from each other. When two handles are released, the retainer housing slides back over a dowel pin attached to the sensing plate and the retainer bars return to their initial position. A plunger's disc can be securely held by the retainer bars without introducing error in the sensing of the pushing force of the syringe plunger.