To provide an electronic type water meter which can carry out accurate integration and reverse judgment by intermittently supplying a current to a magnetic sensor to lower consumed current gradually.

One of the cycles of signals (a) and (b) to be outputted from a magnetic sensor 1 is measured by a cycle measuring section 5 and when the results of the measurement exceed a specified cycle, an overflow signal is outputted. Receiving the overflow signal, a stop/fine flow rate mode control section 4 works so that a sampling signal of the magnetic sensor 1 is switched over to a slow sampling. Under a slow sampling state in the stop/fine flow rate mode, when changes in the signal outputted by the magnetic sensor 1 are detected by a state change detecting section 3, a control is made to switch the sampling signal to a fast sampling.