To reduce the number of power lines of a load and the number of power regulators, and to achieve high-speed phase control.

First to ninth heaters 2-1 to 2-9 heating a hot plate 1 are connected to crossing parts of three first power lines L1-1 to L1-3 and three second power lines L2-1 to L2-3 which are virtually arranged in parallel to a lateral (row) and vertical (column) directions, respectively. First to sixth power regulators 3-1 to 3-6 are controlled and each of the heaters 2-1 to 2-9 are selected and driven. The power regulators 3-1 to 3-6 control open/close of the opening/closing means 10 in synchronization with a synchronizing signal generated in a synchronizing signal generating means 7 of the first power regulator 3-1.