In order to address the problem in that, by increasing the gate resistance of a power semiconductor element, while variation of switching time can be controlled, loss due to the gate resistance becomes larger and power efficiency for the entire system is lowered, the present invention provides an insulating substrate capable of uniformizing switching speeds of circuit elements while suppressing influence on power efficiency of the circuit elements. In the insulating substrate according to the present invention, part of a wiring layer is formed as a control signal circuit layer, and part of the control signal circuit layer is formed as a resistance layer that increases input resistance when the circuit element receives a control signal.