PURPOSE: To provide an excellent moving property and a break-down voltage value in a normal temperature by blending polysiloxanes, an inorganic filler and compatibility agent having siloxane junction as a main chain.

CONSTITUTION: An insulating composite is composed of by polysiloxane, an inorganic filler and compatibility expressed by the formula. In the formula, at least one of Z1 to Z3 is to be a hydrophilic group or a hydrolytic functional group. The inorganic filler to be filled into polysiloxane is an important component for reinforcing a polysiloxane, incombustibility at the time of heating, electric insulation before and after sintering and form maintenance after sintering. Compatibility agent performs mediation of the interface between the inorganic filler and polysiloxane while improving an wetting angle of the inorganic filler and polysiloxane.