The invention provides a casing for a storage apparatus having a first receiving portion for receiving a disc drive box in which a plurality of disc drives are received in a line, the first receiving portion being approximately equal in height and width to the disc drive box, and a second receiving portion for receiving a control portion box in which a plurality of control boards for executing a control relating to a data input and output process with respect to the disc drive are received in a line, the second receiving portion being approximately equal in height and width to the first receiving portion.