The invention provides a method in which an annular or spiral droplet holder formed of wire is used to hold a droplet in a state of being hung therefrom or being contained therein. A means for moving the droplet holder is added to the droplet holder to enable droplet transfer. To merge two droplets, they are brought into contact. To drip the droplet held by a droplet holder formed of wire, the droplet holder is deformed using an external force. A light path which passes through a droplet is set to enable optical measurement. The present invention enables inexpensive, simple droplet transfer. An inexpensive, simple configuration for handling droplets in the fields of chemical analysis, biochemical analysis, and automatic blood analysis can be realized according to the present invention.