The invention discloses a glass mounting structure and an oven. The glass mounting structure comprises a fixing support and a first fixing piece assembled with the fixing support to form a first glass clearance, two sides of the fixing support are respectively provided with a guiding structure protruding to the direction of the first fixing piece, intermediate glass in inserted to the glass clearance and is slidably arranged between the two guiding structures, an elastic piece protruding to the direction of the intermediate glass is arranged on the first fixing piece, a protrusion portion protruding to the direction of the first fixing piece is arranged at the edge of the fixing support, and when the intermediate glass is inserted, the elastic piece is pressed on the intermediate glass so as to enable the intermediate glass to be clamped on the protrusion portion. By the arrangement, the intermediate glass is fixed by cooperation of the fixing support and the first fixing piece, so that the intermediate glass is more conveniently demounted and mounted, and daily cleaning and maintaining is facilitated.