PURPOSE: To easily perform the subject recording and measurement by controlling pressure variation between a vessel for breathing and a vessel for compensation with an electric transducer in using the vessel for breathing containing a specific tensiometer unit and an oxygen generator.

CONSTITUTION: This recorder uses a sensitive electric transducer 3 between a breathing vessel 2 and a compensation vessel. Oxygen is generated by using a tensiometer unit 11 and an electric transducer, and depending upon measuring sensitivity, and connected to an oxygen generator 10 through a circuit 12 for sustaining and controlling flowing speed of the oxygen. The electric transducer 3 is constituted with a semiconductor strain gauge localized on a membrane having 6-20 mm inner diameter and 0.01-0.08 mm thickness and dividing the space of the transducer 3 into two equivalent parts. Oxygen in an amount consumed by an organism is regularly substituted by the same amount of oxygen generated by electrolysis in a breathing cell.