An imaging apparatus including an image pickup unit, a memory which stores moving image data output from the image pickup unit, a detection circuit which detects that free space of a storage capacity of the memory becomes not more than a predetermined amount, a communicating unit which transmits the moving image data to an external device, and a controller which according to output of the detection circuit provided during photographing the series of moving image data, starts to transmit the moving image data stored in the memory to the external device while photographing the moving image data.