To simply, inexpensively, and highly accurately control a command induction spin missile without using a roll gyro by calculating a roll attitude angle of a missile from a roll frequency of the missile.

A signal intensity judgement part 13 detects a received signal maximum point based upon an output of an AGC detector 7, and a pulse is generated. A PLL 14 acts so as to phase lock the signal to a repetition frequency of the pulse, and generates a sine wave in synchronism with a roll attitude angle of a missile. A roll attitude angle calculation part 3 calculates a roll angle based upon an output of the PLL 14, and sends roll attitude angle information to an autopilot 4. In the autopilot 4 a steering instruction amount is calculated on the basis of a calculation result of the roll attitude angle calculation part 3, a processing result of a command processor 9, and a signal of an operation state of the missile detected by a pitch/gyro 10, and a steering apparatus 11 receives the steerirug instruction amount to steer a steering wing 12 for control of a missile body 1.