A ceramic substrate for a semiconductor producing/examining device which has high fracture toughness value, excellent thermal shock resistivity, high thermal conductivity and an excellent temperature rising and falling properties, can be used as a hot plate, an electrostatic chuck, a wafer prober and the like. A ceramic substrate, for a semiconductor producing/examining device, having a conductor formed inside or on the surface thereof has been sintered such that a fractured section thereof exhibits intergranular fracture.