An apparatus comprises an ultrasonic transducer, a probe portion, the proximal end being coupled to the ultrasonic transducer, ultrasonic waves output from the ultrasonic transducer being transmitted to the probe portion, a storage portion which stores the ultrasonic transducer, a cylindrical casing portion which has a distal end and a proximal end and which is installed outside the storage portion, an electric path provided to extend between an electric contact disposed at the distal end of the casing portion and an electric cable connecting portion provided at the proximal end of the casing portion, and an electric cable which has a distal end and a proximal end, the proximal end being connected to a power supply unit, the distal end being coupled to the electric cable connecting portion, the electric path being disposed between the storage portion and the casing.