In an electronic sphygmomanometer, a CPU inlets air into a closed space, including an air bladder in an arm band, an air tube, and another air tube up to a predetermined pressure using a pump, maintains the closed space in a closed state for a certain time, and monitors a decrease in pressure within the maintained time using a pressure sensor. A determination that the air leakage is generated in the closed space including the air bladder and the air tubes is made when the pressure is decreased lower than an allowable amount or more. Similarly, the inspection is also performed to a closed space including the other air tube. The CPU determines whether the air leakage is generated and determines whether an air leakage point exists in the space including the air bladder and the air tube or the space including the other air tube.