NOVELTY - The furnace comprises a furnace body provided with a quartz boat whose upper part is provided with a silicon chip. Diffused gas is passed via an upper part of the furnace body via an air inlet pipe and a diffusion processing discharged tail gas discharge pipe. The gas discharge pipe is connected with an upper exhaust fan. The furnace body is provided with an upper opening or a closing door switch device that is provided with a base. The base is provided with a movable upper bracket. The movable upper bracket is driven by a first driven device along the furnace body.    USE - Solar cell silicon wafer diffusion furnace.    ADVANTAGE - The device can be economically manufactured with low labor cost and without deformation.    DETAILED DESCRIPTION - The furnace comprises a furnace body provided with a quartz boat whose upper part is provided with a silicon chip. Diffused gas is passed through an upper part of the furnace body through an air inlet pipe and a diffusion processing discharged tail gas discharge pipe. The gas discharge pipe is connected with an upper exhaust fan. The furnace body is provided with an upper opening or a closing door switch device. The switch device is provided with a base that is provided with a movable upper bracket. The movable upper bracket is driven using a first driven device along the furnace body in axial direction. The first drive device is provided with a rotating rod and a push-pull rod for pushing a second driving device in the base. The movable bracket, the first driving device, the rotating rod, the push-pull rod and the second driving device are located in a shaft central line of the furnace body. The second driving device is fixed on the movable bracket through the rotating shaft. The rotating rod is fixed on a front upper end on the door. A front end of the push-pull rod of the rotating shaft is fixed on an upper end of the rotating rod and the second driving device. The second driving device is connected with the push-pull rod for pushing the rotating rod to drive the door. The furnace further comprises a compression spring whose front end is fixed on a rotating rod. The compression spring is connected with the push-pull rod. The first and second driving devices are cylindrical type driving devices.