A ceramic heater comprising: a substrate containing a ceramic; and a resistor embedded in the substrate and containing another ceramic, the resistor including two lead portions (31a, 31b) extending parallel to each other, a joint portion that connects one end of one lead portion to one end of the other lead portion, and an electrode portion (27, 28) that is formed integrally with at least one lead portion of the two lead portions (31a, 31b), said electrode portion (27,28) has an end portion connected to the one lead portion (31a, 31b), extends in a direction crossing an axial line (C11, C12) of the one lead portion (31a, 31b), and has another end portion exposed at an outer surface of the substrate; wherein, in a cross section of the electrode portion (27,28) that is taken along an imaginary plane passing through the axial line (C11, C12) of the one lead portion (31a, 31b) and parallel to an extending direction of the electrode portion, the following expression is satisfied: 0.1 ≤ A / B ≤ 0.8, where A is a length of the other end portion parallel to the axial line (C11, C12), and B is the length of the one end portion parallel to the axial line (C11, C12); characterized in that: in the cross section of the electrode portion, c is configured to be different from d, where c is a length that extends along the axial line (C11, C12) formed between an edge of the one end portion located opposite the joint portion with respect to the axial direction (C11, C12) and an edge of the other end portion located opposite the joint portion with respect to the axial direction (C11, C12), and d is a length that extends along the axial line (C11, C12) formed between an edge of the one end portion located on a side toward the joint portion with respect to the axial direction (C11, C12) and an edge of the other end portion located on the side toward the joint portion with respect to the axial direction (C11, C12). a substrate containing a ceramic; and a resistor embedded in the substrate and containing another ceramic, the resistor including two lead portions (31a, 31b) extending parallel to each other, a joint portion that connects one end of one lead portion to one end of the other lead portion, and an electrode portion (27, 28) that is formed integrally with at least one lead portion of the two lead portions (31a, 31b), said electrode portion (27,28) has an end portion connected to the one lead portion (31a, 31b), extends in a direction crossing an axial line (C11, C12) of the one lead portion (31a, 31b), two lead portions (31a, 31b) extending parallel to each other, a joint portion that connects one end of one lead portion to one end of the other lead portion, and an electrode portion (27, 28) that is formed integrally with at least one lead portion of the two lead portions (31a, 31b), said electrode portion (27,28) has an end portion connected to the one lead portion (31a, 31b), extends in a direction crossing an axial line (C11, C12) of the one lead portion (31a, 31b), and has another end portion exposed at an outer surface of the substrate; wherein, in a cross section of the electrode portion (27,28) that is taken along an imaginary plane passing through the axial line (C11, C12) of the one lead portion (31a, 31b) and parallel to an extending direction of the electrode portion, the following expression is satisfied: 0.1 ≤ A / B ≤ 0.8, where A is a length of the other end portion parallel to the axial line (C11, C12), and B is the length of the one end portion parallel to the axial line (C11, C12); characterized in that: in the cross section of the electrode portion, c is configured to be different from d, where c is a length that extends along the axial line (C11, C12) formed between an edge of the one end portion located opposite the joint portion with respect to the axial direction (C11, C12) and an edge of the other end portion located opposite the joint portion with respect to the axial direction (C11, C12), and d is a length that extends along the axial line (C11, C12) formed between an edge of the one end portion located on a side toward the joint portion with respect to the axial direction (C11, C12) and an edge of the other end portion located on the side toward the joint portion with respect to the axial direction (C11, C12). in the cross section of the electrode portion, c is configured to be different from d, where c is a length that extends along the axial line (C11, C12) formed between an edge of the one end portion located opposite the joint portion with respect to the axial direction (C11, C12) and an edge of the other end portion located opposite the joint portion with respect to the axial direction (C11, C12), and d is a length that extends along the axial line (C11, C12) formed between an edge of the one end portion located on a side toward the joint portion with respect to the axial direction (C11, C12) and an edge of the other end portion located on the side toward the joint portion with respect to the axial direction (C11, C12).