To provide an ultrasonic sensor (ultrasonic type liquid detection device) capable of reducing wrong detection caused by being mounted near the shoulder of a liquid vessel.

A clocking circuit 108 is composed so as to start clocking processing from the time when an unillustrated prohibited period signal from a CPU 103 is received, and to stop the clocking processing when an unillustrated burst wave from a comparator 106 is received, and to allow the CPU to output a digital signal of the clocking result as a receiving time. The CPU is composed so as to output the prohibited period signal to the clocking circuit 108 and the comparator 106, and simultaneously to output an unillustrated driving pulse signal shorter than the prohibited period signal to a piezoelectric transducer driver circuit 102, and to determine existence of liquid based on comparison between the receiving time and a reference time.