To provide a volume meter which makes easy to accurately locate the position of an animal anesthetized for tracheae cannulization during examination in a laboratory regarding the volume meter used for measuring the change in an air volume such as in the examination of a pulmonary function of a small animal.

The volume meter 10 is constituted of a base 14 containing a parallel horizontal guide rail, a movable surrounding part 12 with an open end having a horizontal center axis slidable on the guide rail 26 between opening and closing positions, a fixed surrounding part 16 mounted on the base across the horizontal path, and a support table 18 mounted on the fixed part. The fixed surrounding part includes an inner face 38 facing the open end of the surrounding part suited for seal-engaging with the open end of the movable surrounding part when the movable surrounding part is at its closing position. The table protrudes into the movable surrounding part when the movable surrounding part is at its closing position, is adjustable in the vertical direction, and has a vertical axis adjustable anglewise.