An apparatus for manufacturing a semiconductor device includes first and second process chambers in a first row in a first direction, third and fourth process chambers in a second row in the first direction, the third and fourth process chambers being spaced apart from the first and second process chambers in a second direction, and the first and third process chambers being arranged in parallel in the second direction to perform a same process, a load-lock chamber at one side of the first to fourth process chambers in the first direction, and first and second transfer chambers directly connected to each other in a third row in the first direction, the third row being between the first and second rows, and each of the first and second transfer chambers including a transfer unit to transfer a semiconductor substrate between the first to fourth process chambers and the load-lock chamber.