To provide a gas burner which can judge the kind of fuel gas.

First, this gas burner sets combustion specification for use in LPG (S1), and ignites a main burner 11 and a sensor burner 12 (S2-S4). If the detected current value Ij of the second frame rod 42 is below a specified value, this judges gas ignition abnormal (S6), and extinguishes both burners 11 and 12 (S7). Moreover, if the current value Ij is not less than a specified value and besides the detected current value Im of the first frame rod 41 is not less than a specified value, this judges supply gas LPG and this continues combustion, leaving the combustion specification intact (S9). If the current value Ij is not less than a specified value and besides the current value Im is below a judgment value, this judges the supply gas DME (S10), and extinguishes both burners 11 and 12 once (S11), and set the combustion specification for use in DME (S12), and continues combustion (S9), leaving the combustion specification intact, after going to steps 2-8.