In an image pickup apparatus, a calculation unit calculates an amount of noise and an amount of afterimage that can be included in an electric signal or image data in an image pickup operation, based on output characteristic information indicating a manner in which the amount of noise and the amount of after image change as a function of an elapsed time since a voltage is applied to a detection unit, a temperature of the detection unit detected by a temperature detection unit, the voltage supplied to the conversion elements from a power supply unit, and an image pickup operation start time indicating a time elapsed since the supplying of the voltage to the detection unit is started until the image pickup operation is started to output the electric signal corresponding to an electric charge generated by the conversion element in the detection unit.