Abstract: A radial-flow reactor, especially for carrying out endothermic, catalytic reactions, which has a closed reactor housing defining a reactor chamber therein, a centrally arranged, first inlet duct for entry of a gaseous reactant stream and a catalyst bed disposed around the duct located within said chamber, and at least one additional outlet duct arranged on the outer rim of the housing for discharge of a gaseous product stream from said reactor chamber. A plurality of heating elements are embedded in the catalyst bed. Each heating element is constructed as a straight heating tube and each tube has one free end projecting into the reactor chamber, with a part adjacent to the other end attached to a base plate. The base plate forms a part of a wall structure defining the reactor chamber within said housing and can be detached from the wall structure. A group of the heating elements is secured to one base plate so that the group of elements and the one base plate can be removed from the reactor together.