the missile 10 the canister 20 is divided by a partition wall 28 b into a first chamber i for housing the missile 10 and a second chamber ii excluding the first chamber i the canister 20 which houses the missile 10 mounted in the first chamber i protects the missile 10 from external effects such as humidity and from foreign substances serves as a cylinder that pushes the missile 10 out when the missile 10 is to be launched and is provided with a front cover 21 covering the front portion of the missile 10 a rear cover 22 protecting an ejection system and supporting an impact load upon launching a missile restraining tube 28 connected to the rear cover 22 and mounting the tail end of the missile 10 the gas generator 10 and the like thereon a plurality of tubes 23 to 27 each formed in a hollow cylindrical shell shape between the missile restraining tube 28 and the front cover 21 tube connecting parts 23 a to 27 a connecting between the tubes 23 to 27 and guide rails 29 extended lengthwise on an inner wall of the canister 20 along the longitudinal direction of the missile 10 so as to prevent in cooperation with the obturator 80 the rolling motion of the missile 10 during the missile 10 is ejected that is the first chamber i of the canister 20 is formed by the front cover 21 the.