A silane master batch for use in producing a master batch mixture prepared by mixing 0.003 to 0.3 part by mass of an organic peroxide, 0.5 to 400 parts by mass of an inorganic filler, and more than 2 parts by mass and 15.0 parts by mass or less of a silane coupling agent, with respect to 100 parts by mass of a resin containing a halogen-containing resin, and a silanol condensation catalyst,
- wherein the silane master batch is obtained by melt-kneading all or part of the resin;
- the organic peroxide, the inorganic filler and the silane coupling agent, at a temperature equal to or higher than a decomposition temperature of the organic peroxide.