PURPOSE: To decrease space and also to simplify maintenance by using a train speed checking device for which a speed checker for ATS and a speed checker for ATC are used in common.

CONSTITUTION: In ATC section a signal is inputted from ATC signal receiver 12 through an input buffer circuit 30, and a predetermined address of a momeory circuit 27 is designated by each signal through an address setting circuit 31. Each designated address has a pattern speed corresponding to each signal written in binary number, and the pattern speed is given to a comparator 24. The train speed and the pattern speed are subjected to comparison, and when the train speed is lower than the pattern speed, a relay 29 is excited through an amplifier 28, a brake is loosened and thus an output is commanded. When the train comes into ATS section, an ATS signal receiver 7 is actuated, and ATS signal is given to a speed checker 2 instead of ATC signal.