PURPOSE: To provide the laser beam emitting unit which accomplishes simultaneously and easily intensification of a spatter removing effect, prevention of optical pollution by reflection of spatters, prevention of nozzle clogging and observability of plasma and cover glass.

CONSTITUTION: A holder 31 is located between a laser beam emitting port 2 and a single lens 4, demarcates passing space through which a laser beam is passed, has first and second blow-air blowoff parts 31a and 31b to blowoff the blow air, besides, consists of only an inner wall surface part to demarcate the passing space and at least is not provided with a baffle member to baffle blowoff of the blow air in the blowoff direction of the blow air. Namely, in order to reduce the reflection of spatters, the shape eliminating the whole wall surface other than a blowoff port of the blow air, a funnel-shaped assisting gas nozzle part 8 and a column to hold these is provided on an intermediate path till attaining the single lens 4 from works to be welded.