PURPOSE: To make it possible to track a radiowave emitting source more quickly and accurately, by using the control of a received frequency in a receiver and a target memory wherein signals are stored efficiently, and performing the judgment of priorities efficiently.

CONSTITUTION: A guiding apparatus is provided with the following parts: an address generator 15 which generates addresses to be stored in a memory based on frequency control data, pulse width data, angle control data and angle error data; a target memory 16 wherein amplitude data and pulse arriving times are stored based on the address generated in the address generator 15; a tracking data memory 10 wherein the pulse repetition time of a radiowave emitting source to be tracked is stored; and an index memory 17 wherein the number of the received waves having a specified amplitude is stored. A tracking and guiding controller 9 guides a mother machine to the radiowave emitting source stably based on the following data: the received wave data from the memory 17; the angle error data written in the memory 16; the transmitted data such as pulse-width data; the frequency data from the frequency discriminator 11; and the antenna angle data from an antenna servo 3.