There is provided a command supply device capable of effectively supplying a command string forming a loop with a small hardware amount. The command supply device (101) includes: a loop command buffer (113) for accumulating a first part command string which is a head of a first command string before again supplying a first command string repeated supplied to a central processing unit (10) among command strings stored in a main storage device (1); a coupling command buffer (115) for supplying the first part command string accumulated in the loop command buffer (113) to the central processing unit (10) while accumulating a second part command string subsequent to the first part command string when repeatedly supplying the first command string to the central processing unit (10); and a selection circuit (116) for supplying a command subsequent to the first part command string from the second part command string accumulated in the coupling command buffer (115) to the central processing unit (10) when all the fist part command strings have been supplied to the central processing unit (10).