A heating device, comprising: a cylinder body, in which a heating chamber having a pick-and-place opening is defined, and the heating chamber is configured to place an object to be processed; a door body, disposed at the pick-and-place opening and configured to open and close the pick-and-place opening; an electromagnetic generating module, configured to generate an electromagnetic wave signal; and a radiating antenna, disposed in the cylinder body and electrically connected with the electromagnetic generating module to generate electromagnetic waves of a corresponding frequency according to the electromagnetic wave signal, wherein the peripheral edge of the radiating antenna is formed by smooth curves, a smooth curve being a curve of which the first derivative of the curve equation is continuous, so as to make the distribution of the electromagnetic waves in the heating chamber more uniform, wherein the geometric center of the radiating antenna coincides with the center of the maximum cross section of the heating chamber taken along an imaginary plane parallel to an installation plane of the radiating antenna, characterized in that the cross section is rectangular or oblong; and the radiating antenna is in a shape of an oblong, and the length direction of the radiating antenna is parallel to the length direction of the cross section, wherein the length of the radiating antenna is 9/20 to 7/10 of the length of the cross section; and/or the width of the radiating antenna is 3/10 to 13/20 of the width of the cross section; and/or the fillet of the radiating antenna is 2/7 to 1/2 of the width of the radiating antenna, wherein the cylinder body is made of a metal; and the radiating antenna is horizontally disposed at a height of 1/3 to 1/2 of the cylinder body. a cylinder body, in which a heating chamber having a pick-and-place opening is defined, and the heating chamber is configured to place an object to be processed; a door body, disposed at the pick-and-place opening and configured to open and close the pick-and-place opening; an electromagnetic generating module, configured to generate an electromagnetic wave signal; and a radiating antenna, disposed in the cylinder body and electrically connected with the electromagnetic generating module to generate electromagnetic waves of a corresponding frequency according to the electromagnetic wave signal, wherein the peripheral edge of the radiating antenna is formed by smooth curves, a smooth curve being a curve of which the first derivative of the curve equation is continuous, so as to make the distribution of the electromagnetic waves in the heating chamber more uniform, wherein the geometric center of the radiating antenna coincides with the center of the maximum cross section of the heating chamber taken along an imaginary plane parallel to an installation plane of the radiating antenna, characterized in that the cross section is rectangular or oblong; and the radiating antenna is in a shape of an oblong, and the length direction of the radiating antenna is parallel to the length direction of the cross section, wherein the length of the radiating antenna is 9/20 to 7/10 of the length of the cross section; and/or the width of the radiating antenna is 3/10 to 13/20 of the width of the cross section; and/or the fillet of the radiating antenna is 2/7 to 1/2 of the width of the radiating antenna, wherein the cylinder body is made of a metal; and the radiating antenna is horizontally disposed at a height of 1/3 to 1/2 of the cylinder body.