The invention relates to a volume measuring device and volume change measuring method. The invention provides the volume measuring device which can more accurately measure the volume change. The volume measuring device is used to measure volume of thermosetting resin at thermal curing, and is characterized by comprising a heating pedestal part for heating the thermosetting resin, a placing part (13) for placing the thermosetting resin, a heater (16) for heating the heating pedestal part, a thermocouple (17) for measuring the temperature of the heating pedestal part, a temperature regulator (19) for controlling the temperature of the heater based on the temperature measured by the thermocouple, and a laser displacement meter (20) for measuring volume of the thermosetting resin (18) placed at the placing part (13) under various temperature. The placing part (13) is formed on the heating pedestal part with an pit shape, and at least the inner surface of the pit shape is form by raw materials with a surface tension energy of more than 15 mN / m and less than 30mN / m. The heating pedestal part has a heating platform (10) and a carbon fluoride resin plate (11) arranged on the upper surface of the heating platform, and the carbon fluoride resin plate is formed with the placing part (13).