An ultrasonic actuator including: a vibration member, which comprises a plurality of piezoelectric displacement sections each being expanded and contracted by electric signals, and a connection section to connect the plurality of piezoelectric displacement sections, wherein the vibration member is vibrated by resonance of the plurality of piezoelectric displacement sections; and a movement member which generates relative movement to the vibration member by being pressed and contacted with the vibration member, wherein the plurality of piezoelectric displacement sections and the connection section are formed in one body with one and the same material.