This Japanese Industrial Standard specifies the method for determination of concentration of boron contained in exhaust which is generated by combustion of coal, waste, biomass, etc. and discharged to gas flue, chimney, duct, etc. (hereafter referred to as "flue gas"), by collecting and analysing particulate and gaseous boron respectively, and then by totalling their results. The particulate boron is a general term for boron and its compound contained in the particulate matter collected by the filter of 99.5 % or over in collection efficiency to the particle of 0.3μm, and the gaseous boron is a general term for boron and its compound which pass through the filter.