A method of approaching a probe to a target position on a sample mounted on a sample stage tilted at a preselected tilt angle about a tilt axis of the sample stage. Information is recorded in the first group unit. The power converter actuates the DC power capacitor to supply a current via the high-frequency filter to reduce the reactive and harmonic components of load current. If so, the graphics memory control component transforms the virtual address supplied by the central processor to a system address suitable for use in locating the graphics operand in the memory.