In curtain coating for multiple layers consisting of lower most layer, uppermost layer and intermediate layer, using coating liquid having viscosity more than 300 mPas for one layer or more of multiple layers improves amazingly the curtain coating stability against disturbance such as passing spliced portion of running web. The one layer or more layers for which coating liquid having viscosity more than 300 mPas is to be used is selected from intermediate layer. The curtain coating stability is further improved by combining the high viscosity coating liquid for intermediate layer with other technologies such as electrifying web, heating web upstream of coating point and/or keeping web tension higher than some specified value.