A laser beam irradiation apparatus comprises: a laser oscillator; an optical fiber for transmitting a laser beam oscillated by the laser oscillator; an optical tube for accommodating an end of the optical fiber, and for performing a rectilinear motion on a plane perpendicular to a direction in which the laser beam is irradiated; and a pair of piezoelectric transducers disposed between the optical tube and the end of the optical fiber, and having first ends supporting the optical fiber. Each piezoelectric transducer performs a rectilinear reciprocating motion in a direction perpendicular to the other piezoelectric transducer on a plane perpendicular to the direction in which the laser beam is irradiated.