To provide a MOSFET antiphase control dimmer capable of increasing the load rating of equipment through limitng of rush current.

A phase control dimmer, having a built-in MOSFET part 1 with two MOSFET parts connected in series with an AC power supply E in the opposite directions and a built-in drive power supply part 2 for driving the MOSFET part 1, and subjecting the AC power supply E to antiphase control by means of the MOSFET part 1 for controlling the power supplied to load, is provided with a current detection part 4 for detecting the current flowing in the MOSFET part 1, a comparison circuit part 5 for monitoring the output of the current detection part 4, a transistor 6 connected to the MOSFET part 1, and a timer circuit 7 for operating the transistor 6. When a rush current is detected, the MOSFET part 1 is turned off for a certain time and this action is repeated until the rush current is no longer detected, whereby the on width of a control signal is limited irrespective of the on width, so that the current flowing in the MOSFET part 1 becomes less than a predetermined value.