An apparatus includes a detecting unit having pixels that converts radiation or light to electric signals; a drive circuit that drives the detecting unit; a read circuit that outputs the electric signals as image signals; a power supply unit that supplies voltages to the detecting unit, the drive circuit, and the read circuit; and a control unit that controls at least the drive circuit and the power supply unit. The control unit performs a first process of stopping the voltage supply operation to the detecting unit, with the voltage supply operations to the drive circuit and the read circuit maintained; a second process of driving the detecting unit; and a third process of stopping the voltage supply operations to the drive circuit and the read circuit.