A voltage measurement device includes a first group of switches Q1, Q2, a
second group of switches Q7, Q8 and a third groups of switches Q5, Q6. By
turning on the third group of switches Q5, Q6, the first group of
switches Q1, Q2 are turned on, so that a condenser C1 is charged by
voltage impressed between a voltage input terminal A and a voltage input
terminal B. While the first group of switches Q1, Q2 are turned off by
tuning off the third group of switches Q5, Q6, the second group of
switches Q7, Q8 are turned on, so that voltage retained in the condenser
C1 is generated between a voltage output terminal G and a voltage output
terminal H.