The present invention provides a ceramic circuit board including: a ceramic substrate; a plurality of metal circuit plates bonded to a surface of the ceramic substrate; and parts including semiconductor element integrally bonded to a surface of the metal circuit plates through a solder layer, wherein at least peripheral portion of one metal metal circuit plate to which the parts are solder-bonded and is adjacent to the other metal circuit plates is formed with a projection for preventing solder-flow. According to the structure described above, there can be provided a ceramic circuit board which is free from short-circuit due to the solder-flow or bonding defects of the parts thereby to have an excellent operating reliability, and is capable of being easily mass-produced with a high production yield.