PURPOSE: To prevent the miscounting so as to enable a user to set a proper counting speed in response to the count inputs to be actually counted by the user by setting the highest counting speed according to an input speed and counting the count inputs at the set highest speed.

CONSTITUTION: A counter 1 includes an input circuit 7 to which various inputs are given, a counter LSI 8 which counts the count inputs and also sets a counting speed range, an output circuit 9, a liquid crystal display part 2, a key operation part 10, a learning mode changeover switch 5, a width setting switch 6, and power circuit 11. When a learning mode is set and the count inputs to be actually counted are given, the counter 1 measures the input speed of every count input and sets the highest counting speed according to the measured input speed to count the count inputs at the set highest speed. Thus the highest counting speed is set in response to the input speed of the count inputs to be actually counted by a user.