To reduce the cost of amorphous silicon photovoltaic modules, a monolithic structure and an encapsulation process with liquid resin has been developed. The line speed of the encapsulation process can be up to 190 cm/min with a simple apparatus, which corresponds to 40 MW/y. The process was applied with actual amorphous silicon photovoltaic modules with a size of 910 x 455 mm(2). The aperture efficiency of the photovoltaic module was 10.6% (41.9 W). The modules passed five acceleration tests stated in JIS C 8917, i.e., dump-heat test, salt-mist cyclic lest and humidity-freeze test. Field tests which have been carried out in Japan and Arizona assured that the encapsulation with liquid resin is as reliable as the conventional encapsulation with EVA/Tedler. The cost of the liquid resin could be reduced to 80% of original one without reducing reliability, by investigating the recipe of an organic compound.