Abstract: A laser operation device for insertion into a region to be irradiated and which is optimally used as an introcular device to treat cataracts, glaucoma or the like. The device has a hand piece and a probe which is to be inserted into the region to be irradiated. A first fiber portion guides light from a laser light source to the hand piece, a second fiber portion connected with the first fiber portion at a connection surface thereof introduces light from the first fiber portion to the region to be irradiated. A first terminal formed to an end of the first fiber portion and a second terminal formed to an end of the second fiber portion are connected by a split sleeve, so that alignment between the first fiber portion and the second fiber portion is facilitated. Buffers around the first fiber and the second fiber protect the respective fibers from damage. Even if the second fiber portion were destroyed, safe and accurate incising operation can be applied to eye tissue or the like.