A laser processing device converges laser light at an object to be processed having a silicon part containing silicon mounted on a glass part containing glass with a resin part interposed therebetween so as to form a modified region within the object along a line to cut. The laser processing device comprises a laser light source emitting the laser light, a spatial light modulator modulating the laser light emitted from the laser light source, and a converging optical system converging the laser light modulated by the spatial light modulator at the object. When forming the modified region in the glass part, the spatial light modulator displays an axicon lens pattern as a modulation pattern so as to form converging points at a plurality of positions juxtaposed close to each other along a laser light irradiation direction.