An automatic packaging apparatus has an arraying and supplying station, a sorting station and a packaging station. The arraying and supplying station forcibly arrays and supplies encased products to orient their caps in one direction. The sorting station selectively sorts the arrayed encased products to a first feed path for feeding the encased products to package the encased products in a abreast-arrayed attitude and a second feed path for feeding the encased products to package the encased products in a tandem-arrayed attitude. The packaging station automatically packages the encased products by a shrink sheet in the abreast-arrayed attitude or the tandem-arrayed attitude.