The invention discloses an electronic control box which is provided with a receding groove. The receding groove isolates the internal space of the electronic control box and the external space of theelectronic control box. A sealing portion is arranged on the electronic control box. The sealing portion forms the receding groove. The electronic control box comprises a box body and a box door. An opening of the box body is provided with a first notch. The box door is provided with a second notch. The sealing portion is formed by a bottom plate and a side plate. The bottom plate and the side plate form the structure with an opening formed in the top end and an opening formed in one side in an enclosure manner. The opening face of the top end of the sealing portion is in sealing connection with the inner surface, located on the second notch, of the box door. The opening face of one side of the sealing portion is attached to the inner wall face, located on the first notch, of the box body.The invention further discloses an air-conditioner comprising the electronic control box. Compared with the prior art, a door handle of the box door is well receded, the leakproofness of the electronic control box is kept, the electronic control box and the electronic control box door are close to each other through folding edges, the dustproof and mothproof effect is achieved, and the safety ofthe electronic control box is improved.