A calculating apparatus includes a baseplate, a first mother board module and a connection module. The baseplate includes a bottom surface having a first component layout region, a second component layout region and a connection component layout region all arranged in order from a first side to a second side of the bottom surface. The first mother board is drawably disposed at the first component layout region of the bottom surface. The first mother board includes a first tray, a first control board, and a first electronic hard disk drive. The connection module is electrically connected to the first mother board module so that the first mother board module is capable of performing external communication through the connection module.