PURPOSE: To prevent the re-sucking of a liquid specimen, by providing a piston member of which the lower end is made freely slidable up and down in a cylinder member and which is energized upwardly and an engaging member engaging the piston member with the cylinder member.

CONSTITUTION: When a finger is separated from a push button 21, a piston rod 20, a cylinder 30 and engaging member 40 are transferred from the state of Fig.3 to the state of Fig.2 by the energizing forces of an upper spring 51 and a lower spring 52 and subsequently returned to the state of Fig.1. Therefore, by the transfer from the state of Fig.3 to the state of Fig.2, the piston rod 20 and the cylinder 30 integrally rise by a distance d2 and the leading end of a dripping chip 1 also rises. When the piston rod 20 and the cylinder 30 integrally rise, both of them generate no relative motion and, therefore, the re-sucking of a liquid specimen is prevented and the leading end of the dripping chip 1 can be separated from the liquid specimen.