To provide an automatic flushing type closet bowl, in which feces in the closet bowl is surely detected more directly and the convenience of a user and water saving are realized by automatically supplying flushing water accurately and which has a simple structure and is assembled and maintained easily.

A transmission means 12 and a reception means 13 are fixed onto the rear of a water collecting section 11 for the closet bowl 10 made of pottery. Microwaves transmitted from the transmission means 12 are transmitted through pottery and propagated in collected water, and further transmitted through pottery, received by the reception means 13 and output to a phase- difference measuring circuit 16. The phase-difference measuring circuit 16 obtains the phase lag θ1 of microwaves being propagated in collected water to microwaves directly received through a power splitter 15 from a microwave oscillator 14 and outputs it to a control section 17. The control section 17 detects the presence of feces in collected water on the basis of the phase lag θ1, and controls the supply of flushing water by opening and closing a flushing- water feed valve 18.