Disclosed are an apparatus and method for visualizing subsurface velocity structure by processing signals through waveform inversion in the Laplace-Fourier domain, and a recording medium storing a program for implementing the method. A receiver receives a seismic signal from a target region, and a signal processor processes the seismic signal to generate image data for visualizing the subsurface structure of the target region. The signal processor performs the waveform inversion in the Laplace-Fourier domain, thereby obtaining a velocity model similar to an true structure of the target region.