a baking oven for heating lead frames used in the manufacturing of semiconductor devices including an oven main body having an entrance and an exit for lead frames , a heating device which creates a high - temperature atmosphere inside the oven main body , a lead frame magazine installed inside the oven main body so as to accommodate lead frames in a stacked fashion , a magazine mover which moves the lead frame magazine in a vertical direction , and a width adjustment device that changes the width of the lead frame magazine in a horizontal direction . the magazine mover and the width adjustment device are provided outside the oven main body for securing a high lead frame accommodation capacity and a longer heating time of the oven .