An image pickup apparatus capable of completing photography normally without falling in a low battery (LB) state in the middle of the photography in case of performing the photography with a light emitting device such as an LED emitting light is disclosed. The maximum current value (the maximum light emission amount) of the LED is calculated by the LED maximum current operation unit from the electric power source voltage value obtained by an electric power source control circuit and the data read from a memory. Hereupon, the current operation unit calculates the maximum LED current value at which the electric power source voltage dropping by the light emission of the LED does not become the minimum drive voltage (LB) or less of the image pickup device.