An apparatus for testing a wafer includes a wafer chuck on which the wafer is loaded to perform a wafer test process. The wafer chuck is maintained at a high temperature in a predetermined temperature range. The apparatus for testing a wafer further includes a wafer handling arm supporting the wafer and transferring the wafer to the wafer chuck, and a wafer heating module coupled to the wafer handling arm, arranged parallel to the wafer, and preheating the wafer to be loaded on the wafer chuck.