This research was tried to suggest ultrasonic sensor to measure the amount of high pressure gas. The directivity curve experiment device was designed to experiment, and experiment sensor used six types according to thickness of matching layer. Experiment was conducted in based on 70 kHz of transferred frequency, and experiment distance was set 1 meter. Result of experiment, sensor of type F showed increasing efficiency of 10% higher than base in case of receiving strength and sensor of type-a that is most thin shape showed most wide angle in case of response curve. This study will be a basic study to determine the standard of the sensor according to tank size.