Provided are an optical fiber which has good laser beam condensation efficiency and is highly resilient, and a shockwave generating device employing same. An optical fiber (11) is employed in an underwater shockwave generating device (10) which projects a laser beam underwater and generates an underwater shockwave. The optical fiber (11) comprises: a main body part (16) and a laser convergence part (17) which is disposed upon a leading end thereof. The laser convergence part (17) is configured so as to exhibit an approximately frustum shape wherein the diameter of the leading end (18a) is narrower than the diameter of the base end (18b), and such that an interior angle ¸ with respect to a radial direction of a lateral face of an axial cross-section gradually decreases toward the front thereof.
