PURPOSE: To decrease to the utmost a delay extending from a time point when an initial value is set actually to a counter to a time point when an initial value detecting signal is outputted, and also. to prevent a whisker pulse from being generated in the initial value detecting signal with regard to the counting device having an initial value detecting circuit for detecting a fact that the counter in the device generates the initial value as its counting value.

CONSTITUTION: This device is provided with a counter 1 by which a value designated by an initial value signal IV is set as an initial value in the case an initializing signal IZ and the initial value IV are applied, and thereafter, a variation timing of a value of a signal RO of a counting object is counted and outputted as a counting value signal, CC, and an initial value detecting circuit 2 for detecting a fact that the initial value is set to the counter 1 by latching the initializing signal IZ by the variation timing of the value of the signal RO of the counting object.