PURPOSE: To be able to quickly attach and detach a wafer by imprinting positive and negative pulse alternating voltage at different phases into multiple electrodes placed in an insulation body and to attach the wafer by the static electricity produced.

CONSTITUTION: For the electrodes A1, A2, A3, B1, B2 and B3, 12 wedge-shaped electrode boards are placed in a circular format, the insulation body 11 is a silicon resin, and when the platform 12 is an etching system, these are set up as conductive electrodes. With this structure, a reverse alternating voltage is applied on electrodes with the same code number during the same phase, the pulse voltage is divided into 3 phases, and reverse voltage is applied with same phase on A1 and B1, A2 and B2, and A3 and B3, respectively. For the time intervals between T1 to T2 and T3 to T4, positive and negative voltage is applied in 3 phases while shifting other electrodes. The pulse alternating voltage applied has a voltage strength of 1KV, pulse width of 5sec, and a frequency of about 0.33Hz. If positive and negative voltages are continuously applied on any pair of A and b electrodes, the attachment strength is not lost and since the applied voltage reverses positive and negative polarity in a short time period, it is possible to remove the wafer quickly without any residual polarization.