valve 20 one touch hand valve for harvesting 30 and sampling and harvesting tube lines 60 by opening the one touch hand valve for harvesting 30 at this time it is desirable that gas from the gas supply tube for cultivation 11 is blocked for uniform sampling in consideration of characteristics of cultivation of microorganisms and samples are taken by the one touch hand valve for harvesting 30 as for fig5 gas is continuously supplied by the gas supply tube for cultivation 11 during microalgae cultivation and in case that taking samples are required or harvesting is required after completion of cultivation samples are taken through the gas supply tube for prevention of precipitation 12 of the one touch valve 10 one touch hand valve for harvesting 30 and sampling and harvesting tube lines 60 by opening the one touch hand valve for harvesting 30 at this time it is desirable that gas from the gas supply tube for cultivation 11 is blocked for uniform sampling in consideration of characteristics of cultivation of microorganisms and samples are taken by the one touch hand valve for harvesting 30 furthermore gas for prevention of precipitation of the gas supply tube line for prevention of precipitation 50 is periodically.