To provide a speargun which enables the setting of the sight lighting a game.

A floodlight projector 15 for lighting focusing a light beam into one column is provided at the tip part of a guide part 11 of a speargun body 10 which is constituted of a guide part 11 to guide and fire a spear 20, a grip part 12 to pull a trigger 12a holding it with a hand, and a butt part 13 which is put on a shoulder to support the body 10 of the speargun firmly. A game to be caught is lit concentratedly by the floodlight projector 15 at the tip part of the guide part 11 of the body 10 of the speargun, and the sight of the speargun is set on the game to fire the spear 20.