1. An ultrasonic image generating method for generating an ultrasonic image based on ultrasonic echo data obtained by transmitting/receiving ultrasonic waves to/from an inspection object, the method comprising: a reference position setting step for determining the reference position on each image with respect to a plurality of consecutive two-dimensional tomograms; a correction step for obtaining regular and consecutive two-dimensional tomograms by correcting irregularity of the reference position of each of the two-dimensional tomograms determined by the reference position setting step; and an ultrasonic image generating step for generating the ultrasonic images based on the regular and consecutive two-dimensional tomograms corrected by the correction step.