To obtain a wide range of speed and traveling length and reduce cost by converting reciprocating motion of nearly elliptic orbit of a chain driven by a sprocket rotation into linear reciprocating motion of a moving body by an attachment mounted on the chain.

By driving one of a sprocket by a motor in an arrow direction 9a, a chain 3 proceeds also in an arrow direction 9a, an attachment 10 mounted on the chain 3 inserted in a window 5 of a moving body 4 moves the moving body in left direction of the arrow direction 9a. At the left end of the sprocket 2, the moving body 4 is in an almost stopping state because the attachment 10 proceeds downward of an arrow direction 9b rotating along the sprocket 2. With the movement of the attachment 10, the moving body 4 proceeds in the right in the arrow direction 9b. At the right end of sprocket 2', movement reverses and the moving body 4 can thus make horizontal reciprocating motion.