To provide a photovoltage measuring device which divides voltage without receiving the influence of environmental characteristics, such as, temperature and humidity, and measures a main circuit voltage at high accuracy.

The photovoltage measuring device includes a main circuit conductor 1; a dielectric 2 which supports the main circuit conductor 1 in an insulated state and is fixed to a ground member 3; an embedded electrode 6 buried in the dielectric 2; and an electro-optic element 20 for measuring a voltage of the main circuit conductor 1 connected to the embedded electrode 6. A voltage resulting from voltage division at the capacitance ratio between a capacitance between the main circuit conductor 1 and the embedded electrode 6 and the capacitance between the buried electrode 6, and the ground member 3 is applied to the electro-optic element 20.