Provided is an ultrasonic probe, which uses a composite piezo-electric element, which includes a piezo-electric wafer made of piezo-electric material and having a lattice shape, and a polymer filled between the lattices of the piezoelectric wafer. The ultrasonic probe has a high power and a wide band width simultaneously. In addition, since the ultrasonic probe further includes a heat exhaust unit for exhausting the heat generated at the ultrasonic probe to the outside, the temperature of an acoustic lens which contacts patients may be lowered.