Electrostatic charge and its distribution in the dielectric layer of TiO2- and Cr2O3-added alumina electrostatic chucks has been studied. The electrostatic potential was evaluated,at various applied voltages by an electrostatic potential meter and it demonstrated the existence of charges with opposite polarities. Direct SEM observation and toner development of the charged ceramic surface was carried out to clarify the charge distribution. The charge contrast was not uniform on the ceramic microstructure and the charge was distributed in the form of grains. Taking into consideration these results, the relationship between electrostatic charge distribution and ceramic microstructure is discussed.