In an existing window air conditioner, a filter is laid flat at the air inlet to filter the airflow. In the process of realizing the present disclosure, the inventors have found that the following problems exist in the conventional technologies: the lay-flat filter has a limited filtering area and cannot achieve a very good filtering effect, and the lay-flat filter has the problem of large wind resistance, which causes varying degrees of air pressure loss and air volume loss and reduces the energy efficiency of the equipment, and in the case of multi-direction air intake of the equipment, a plurality of filters at different angles need to be designed separately to adapt to the adjustment for multi-direction air intake, which increases the complexity of the equipment, and increases the work involved in mounting and dismounting of the filters, resulting in the problem of inconvenient use.