The present invention relates to a method and a regenerator for heating gases, by alternatingly first heating heat carriers, preferably a bed of heat carrier bodies, and thereafter utilizing this energy stored by the heat carriers to heat cold gases. The essential feature of the invention is that a loose bed of the heat carriers is located between two coaxial and equidistant grates of the regenerator, and that the hot gas flows through this bed from the inside to the outside during the heating up phase of the regenerator and the cold gas flows through it in the reverse direction, from the outside to the inside, during the gas heating phase. This method and the regenerator provide advantages for gas heating due to lower thermal losses of the regenerator itself, and increased heat transmission is obtained due to large heat exchange surfaces of the heat carriers in a bed with a relatively low pressure loss for the gas flowing through.