To set minimum input low by improving flame stability when adjusting thermal power from high thermal power to low thermal power.

A flame holding part 24 for holding a flame is formed in a space surrounded by the outer peripheral edge 60 of each protrusion 3 of a burner head 20, the lower face of a hood part 26 and a placing surface of the burner head 20 of a burner body 10, and the flame holding part 24 is divided into a triangular upper flame holding part 24a surrounded by an upper outer peripheral edge 60a and the lower face of the hood part 26, and a lower flame holding part 24b surrounded by the lower face of level difference 23, the lower outer peripheral edge 60b of the protrusion 3 and the placing surface. Consequently, even when thermal power is quickly adjusted from high thermal power to low thermal power to weaken the flame inward, the flame is vertically divided and held well in each of the upper flame holding part 24a and the lower flame holding part 24b.