A digital broadcasting transmitter-receiver and method for a portable computer are provided, which can be detachably operated. The digital broadcasting transmitter-receiver for a portable computer can include a case configured to be attached in a bay of a main body, a main substrate installed in the case and mounted with at least one chip that receives a digital broadcasting signal and an antenna partially within the case. An antenna body can reciprocally move to extend outside of the case or the portable computer. With this structure, the digital broadcast can be watched on a conventional portable computer, and expansibility of the portable computer can be increased because users can selectively mount the transmitter-receiver.