A mobile phone apparatus 10 is equipped with a camera module 36 including an image sensor (52), an AE evaluation circuit (60), etc. When a camera function is executed, an exposure is adjusted such that an exposure evaluated value is equal to an exposure target value, whereby, an AF controlling processing is executed. For example, when a shutter key is operated, the exposure target value is changed to an exposure target value for AF control being smaller than an exposure target value for normal photographing. Furthermore, a frame rate is increased such that the exposure evaluated value having a correlation to the frame rate is smaller than the exposure target value in response to the change of the exposure target value. Then, the AF controlling processing is executed on the basis of the image data every frame output from the image sensor (52) at the increased frame rate.