PROBLEM TO BE SOLVED: To provide an improved device for ion treatment in mass analysis. SOLUTION: A segmented rod multipole device 10 has a pair of long and slender segmented rods 20, 22, 24, 26 which delimit a long and slender space therein, and a shaft with a space in a longitudinal direction. Each long and slender segmented rod 20, 22, 24, 26 has a plurality of segments 30, 31, 32, 34, a circuit bringing about RF electric field in the space by applying RF voltage to the long and slender segmented rod, a circuit applying DC voltage to a segment, and the circuit applying DC voltage has a plurality of lead wires. And it has a reaction reagent source 82 communicated with a long and slender space wherein each lead wire is connected with each segment 30, 31, 32, 34 of the long and slender segmented rods and the voltage to each first segment connected with the first lead wire can be controlled separately from the voltage to each second segment connected with the second lead wire. COPYRIGHT: (C)2007,JPO&INPIT
