To solve the problem that a conventional bag or carrying case for transporting a pet such as a dog needs complex and time-consuming processing such as hole making or sewing of a mesh material for ensuring proper airflow, and the problem that a plastic carrying case or the like provided with numerous air holes is bulky and hard to handle even when it is not used and the like.

All the peripheral walls of the bag 1 for enclosing a pet including its bottom part 3 on which a rigid bottom plate 2 is placed are constituted of a breathable cloth material 4. The bag 1 has a closed space 5 for enclosing the pet above the bottom part 3 and has opening and closing parts 6 in the right place. The breathable cloth material 4 is an air mesh material 7, for example. The bag has an opening and closing part is provided with a fastener 15a along the periphery excluding the bottom of the front or back side, and an opening and closing part provided with a fastener 15b along the periphery excluding one end of the top surface.