PURPOSE: A substrate etching apparatus is provided to minimize the etching difference between substrates by uniformly etching the temperature of an etching bath. CONSTITUTION: A transfer unit transfers a substrate. An etching bath(102) etches the substrate transferred from the transfer unit. An etchant tank(105) supplies etchant to the etching bath. An insulation unit(109) surrounds the etching bath and maintains the temperature of the etching bath. The insulation unit includes a temperature measuring unit which measures the temperature of the insulation unit.
