An infusion pump for continuously conveying a fluid includes an inlet, an outlet, a first piston movably supported in a first chamber connected to the inlet, a second piston movably supported in a second chamber connected to the outlet, and a connecting channel connecting the first chamber to the second chamber. At least one control element, in a first position, connects the inlet to the first chamber and, in a second position, connects the first chamber to the second chamber. A controller acts upon the first piston, the second piston, and the control element so that, when the control element is set in the first position, the first chamber is filled while the second chamber is drained, and when in the second position, the first chamber is drained and the second chamber is filled, wherein a constant discharge at the outlet is maintained at a predefined flow rate.