A heater, comprising: a base body, which comprises a first end and a second end opposite to one another, wherein the base body extends along an axial direction between the first end and the second end and is hollow inside to form a heating chamber configured for containing a tobacco substrate; a conductive module, which at least comprises a first conductive portion and a second conductive portion that are arranged on the base body; a far infrared coating, which is attached onto the base body between the first conductive portion and the second conductive portion, wherein the first conductive portion and the second conductive portion are both in electrical connection with the far infrared coating; wherein the first conductive portion comprises a first main part a and a first extending section extending from the first main part along the axial direction of the base body, the second conductive portion comprises a second main part and a second extending section extending from the second main part along the axial direction of the base body, characterised in that the far infrared coating extends from the first main part to the second main part, and in that N is the proportion of a width along the circumferential direction of the base body of the far infrared coating located between the first extending section and the second extending section to a width along the axial direction of the far infrared coating located between the first extending section and the second main part, and/or the proportion of a width along the circumferential direction of the base body of the far infrared coating located between the first extending section and the second extending section to a width along the axial direction of the far infrared coating located between the second extending section and the first main part, and 0.8≤N≤1.2. a base body, which comprises a first end and a second end opposite to one another, wherein the base body extends along an axial direction between the first end and the second end and is hollow inside to form a heating chamber configured for containing a tobacco substrate; a conductive module, which at least comprises a first conductive portion and a second conductive portion that are arranged on the base body; a far infrared coating, which is attached onto the base body between the first conductive portion and the second conductive portion, wherein the first conductive portion and the second conductive portion are both in electrical connection with the far infrared coating; wherein the first conductive portion comprises a first main part a and a first extending section extending from the first main part along the axial direction of the base body, the second conductive portion comprises a second main part and a second extending section extending from the second main part along the axial direction of the base body, characterised in that the far infrared coating extends from the first main part to the second main part, and in that N is the proportion of a width along the circumferential direction of the base body of the far infrared coating located between the first extending section and the second extending section to a width along the axial direction of the far infrared coating located between the first extending section and the second main part, and/or the proportion of a width along the circumferential direction of the base body of the far infrared coating located between the first extending section and the second extending section to a width along the axial direction of the far infrared coating located between the second extending section and the first main part, and 0.8≤N≤1.2.