An image forming apparatus including a first member having a first face, a first protrusion and a second protrusion projecting from the first face, and a groove portion formed in the first face, and a second member having a second face provided with a first hole and a second hole. The first protrusion and the second protrusion are inserted into the first hole and the second hole. The second face is superposed on the first face so that the groove portion located between the first member and the second member is in a visible state. The second face is sandwiched between a part of the first protrusion inserted in the first hole and the first face. The second hole in which the second protrusion has been inserted has a gap between the second hole and the second protrusion in an extending direction of the groove portion.