To prevent resin from leaking out by a method wherein a first solder resist solution having respective specific values of viscosity and solid content is applied by spraying onto a printed circuit board, and after drying, a second solder resist solution having respective specific values of viscosity and solid content is further applied by spraying thereto.

Solder resist solution is applied two times. A first solder resist solution to be applied in the first time has a viscosity of 100-800cP preferably about 400-700cP, and a solid content of 40wt.% or over and preferably about 50-70wt.%. Further, a second solder resist solution to be applied in the second time has a viscosity of 100-900cP and preferably about 500-800cP, and a solid content of 50wt.% or more and preferably about 55-70wt.%. Herein, the viscosity is measured at about 25°C solution temperature and with a Brookfield viscometer (BM type) under the condition of about 60rpm in rotary speed of a rotor.