The present invention relates to a grinding wheel truing tool, its manufacturing method, and a truing apparatus, a method for manufacturing a grinding wheel and a wafer edge grinding apparatus using the same. The tantalum andor niobium containing raw materials are processed by repeated use of a solution of ammonium fluoride. The ECU calculates a first fill hydraulic value in accordance with the time period from the engine start to the garage shift operation. One or more transient DC voltages are applied to the electrodes of the mass analyzer in order to urge ions along the length of the mass analyzer.