Abstract: A pipetting device including a vertical cylinder provided on the lower end portion of a cylindrical housing, a piston working in the cylinder, an actuating rod connected to the piston and extending vertically through the housing, an operating knob mounted on the upper end of the actuating rod, a return spring biassing upwards the actuating rod, and a hollow tip mounted removably on the lower end of the cylinder for receiving liquid therein. The opposite ends of the return spring are connected non-rotatably to the housing and the actuating rod respectively thereby the actuating rod is biassed angularly with respect to the vertical axis thereof. The device further includes guiding mechanism for controlling the downward movement of the actuating rod in normal operating condition and allowing an additional downward movement thereof when the actuating rod is rotated angularly whereby the tip is removed off from the pipetting device.