PURPOSE: To obtain a transfer type photo MOS relay capable of obtaining BBM operation even when a light emitting diode is driven by the same input signal.

CONSTITUTION: A control circuit 2a in a normally-opened side output part 1a is constituted of inserting a resistor element R3 between the source of a MOSFET Q1 and the sources of output side MOSFETs Qa1, Qa2 and connecting a parasitic diode D in parallel with the resistor R3. When a light emitting diode LEDa emits light based upon an input signal voltage, the control circuit 2a in the output part 1a is driven so that the MOSFET Q1 is turned off by the output voltage of a solar battery SCa and current is allowed to flow into the battery SCa, the gates and sources of the MOSFETs Qa1, Qa2, a resistor elements R3, R1, and the circuit of the battery SCa. Since a current value is suppressed by the insertion of the resistor element R3, the charging time of the input capacity of the MOSFETs Qa1, Qa2 is delayed.