Abstract <p>A methodical approach to the study of gas pressure in closed pores of solids by ultrasonic scanning of the sample has been developed. It is proposed to take into account the property of non-perfection of gas in pores, which makes it possible to calculate the gas pressure in closed pores by a nondestructive method. The possibility of isolating the sound velocity in the pore from the total sound velocity in ultrasonic scanning is shown. The data of approximation of sound velocity as a function of pressure for various gases and gas mixtures are presented. The applicability of ultrasonic scanning for experimental determination of pressure in pores for different gases is evaluated.</p>