Abstract: A lens-fitted film unit and production thereof, wherein lens-fitted film unit has a front cover, a rear cover, a main body and a magazine chamber lid to take out a film magazine from a film magazine chamber located in the main body, below the film magazine chamber and at the bottom surface of the lens-fitted film unit. The front cover, rear cover and main body have respectively a rib, and the surrounding of the lower portion of the film magazine chamber is surrounded by the rib of the front cover, the rib of the rear cover and the rib of the main body. After the rear cover is attached, the film magazine chamber lid is attached so that the magazine chamber lid is fixed to the front and rear cover and is not fixed to the main body.