An air-conditioning apparatus comprising: a main body including a frame body and a base body provided on a back surface side of the frame body, wherein a plurality of frame body-side engagement sections that project backward, and a plurality of extension sections that are provided on both sides of each frame body-side engagement section and extend backward, are provided on a back side of the frame body, a plurality of base body-side engagement sections that engages with each of the plurality of the frame body-side engagement sections, and a plurality of support bases that are provided below both sides of each of the base body-side engagement sections and are located below the extension section, are provided on a front side of the base body, and when the frame body is pushed into an inside of the base body, each of the frame body-side engagement sections and each of the base body-side engagement sections engage with each other, and each of the extension sections is supported by each of the support bases, and the frame body is mounted to the base body, wherein each of the frame body-side engagement sections includes a frame body-side claw portion (2a1) that projects upward, each of the base body-side engagement sections includes a base body-side claw portion (3a1) that projects downward, and when the frame body is mounted to the base body, the frame body-side claw portions (2a1) and the base body-side claw portions (3a1) engage with each other, and the support bases support the extension sections at a position of the main body ahead of a position where the frame body-side engagement sections and the base body-side engagement sections engage with each other.. a main body including a frame body and a base body provided on a back surface side of the frame body, wherein a plurality of frame body-side engagement sections that project backward, and a plurality of extension sections that are provided on both sides of each frame body-side engagement section and extend backward, are provided on a back side of the frame body, a plurality of base body-side engagement sections that engages with each of the plurality of the frame body-side engagement sections, and a plurality of support bases that are provided below both sides of each of the base body-side engagement sections and are located below the extension section, are provided on a front side of the base body, and when the frame body is pushed into an inside of the base body, each of the frame body-side engagement sections and each of the base body-side engagement sections engage with each other, and each of the extension sections is supported by each of the support bases, and the frame body is mounted to the base body, wherein each of the frame body-side engagement sections includes a frame body-side claw portion (2a1) that projects upward, each of the base body-side engagement sections includes a base body-side claw portion (3a1) that projects downward, and when the frame body is mounted to the base body, the frame body-side claw portions (2a1) and the base body-side claw portions (3a1) engage with each other, and the support bases support the extension sections at a position of the main body ahead of a position where the frame body-side engagement sections and the base body-side engagement sections engage with each other..