1. An ultrasonic therapy apparatus for focusing a therapy ultrasonic wave at an affected part for therapy, comprising: an applicator having a therapy ultrasonic wave generation source and ultrasonic probe; a mechanism for moving the applicator; a driver for driving the therapy ultrasonic wave generation source so as to generate the therapy ultrasonic wave from the therapy ultrasonic wave generation source; a diagnosis apparatus for driving the ultrasonic probe to scan a focal point and its neighborhood with the ultrasonic wave, forming a cross-sectional image based on an obtained echo and displaying the cross-sectional image; a console for setting a therapy region in a state to include the affected part; and a system controller for performing a therapy simulation, wherein, in the therapy simulation, the mechanism moves the applicator in accordance with a planned course of the focal point designed in a way to correspond to the therapy region, the driver does not drive the therapy ultrasonic wave generation source so that no therapy ultrasonic wave is generated, and the diagnosis apparatus scans the focal point and its neighborhood through the ultrasonic probe and displays, together with the cross-sectional image, a focal point marker representing the focal point.