A garbage collection unit and a garbage collection method in an embedded environment are provided. In the method, a memory is divided into a young generation area including first and second areas and an old generation area including a predetermined number of blocks, the young generation area is divided into two areas, the garbage collection is performed alternately in the first and second areas of the young generation area, and the garbage collection in the old generation area is performed gradually in units of individual frames including a predetermined number of blocks. Accordingly, time delay due to garbage collection can be minimized, thereby guaranteeing a real-time operation.