An apparatus giving the revolution automatically to a cylindrical Pitot-tube was made. The revolution is given by an electric motor, and the revolutionary angle, catched by a synchronus control transmitter, comes out on Y-axis of the X・Y recorder. The static pressure, leaded to a strain gage transducer, draws a curve on X-axis of the X・Y recorder. The velocity measurement of this apparatus is much quicker, and the treatment of one is a simple.