A camera unit having an imaging optical unit having a plurality of free-curved surface prisms for forming subject images; a single imaging device for photoelectrically-converting the subject images from a plurality of directions formed by the imaging optical unit; a signal processing unit for processing the photoelectrically-converted signals from the imaging device and outputting image signals; a communication unit for performing communication with an external unit; and a control unit for controlling operation of the imaging device and the signal processing unit and transmitting the image signals output from the signal processing unit from the communication unit to the external unit, and a camera system using the camera unit.