A white balance adjusting device includes a rotational color filter and a shutter which are provided between a photographing optical system and an electro-developing recording medium having first, second, and third recording areas. Red, green, and blue images are recorded in the first, second, and third recording areas through the rotational color filter. A photometry sensor is provided behind the electro-developing recording medium to sense the intensity of light passing through the first, second, and third recording areas. When the sensed light reaches a proper photometry value, the application of a voltage to the electro-developing recording medium is stopped, and the shutter is closed.