PURPOSE: To provide a volume measuring equipment based on a gas volume method in which the measurement can be made at an arbitrary temperature while shortening the settling time of data and the set temperature can be measured positively through simple operation using a compact structure.

CONSTITUTION: A compositional member 3 of a measuring chamber 1 and an expansion chamber 2 is fixed with a first temperature sensor 4 for measuring the temperature thereof, and a heat-exchanger 5 comprising a Peltier element 51 and a heat sink 52 mounting a second temperature sensor 7. A temperature regulation circuit 6 controls current supply to the Peltier element 51 such that the compositional member 3 has a target temperature while limiting the temperature of the heat sink 52 within a predetermined range.