An insulation problem detection apparatus includes a microcomputer configured to: control a voltage detecting circuit to measure an insulation resistance of a vehicle based on a voltage at which a capacitor in the vehicle is charged, the microcomputer controlling the voltage detecting circuit to connect the capacitor in series to a power supply mounted in the vehicle and a ground of a body of the vehicle to measure the voltage at which the capacitor is charged; obtain a total voltage of the power supply from an external apparatus that is external to the microcomputer when the insulation resistance of the vehicle is measured by the voltage detecting circuit; and detect whether there is an insulation problem of the vehicle based on (i) the total voltage of the power supply obtained from the external apparatus and (ii) the insulation resistance of the vehicle measured by the voltage detecting circuit.