(57) A ceramic circuit board having an external resistor prepared by co-firing a low-bubbling resistor and a glass overcoat in which Ag is used in an amount of 0 to less than 1% by weight with a glass having a deformation temperature not higher than that of the glass of the overcoat in the low-bubbling resistor and a glass of CaO-Al₂O₃-SiO₂-B₂O₃ system is used in the overcoat. Also, in the low-bubbling resistor, Ag may be contained in an amount of at least 1% by weight in combination with a glass having such a deformation temperature that this deformation temperature minus 10 °C is not higher than that of the glass of the overcoat. Addition of Ag to the resistor can render the deformation temperature of the glass of the resistance paste substantially equal to or less than that of the glass of the overcoat, thereby enabling further reduction of the amount of bubbles remaining in the resistor after firing. The low-bubbling resistor not only enables accurate adjustment of the resistivity by laser trimming but also enables stable maintenance of the resistance value after the trimming.