A method of manufacturing a solid state image sensor is provided. The method includes forming electrically conductive layer and an interlayer insulation film above a first region and a second region, performing an annealing process after forming the conductive layer and the interlayer insulation film, and forming a protective film above the interlayer insulation film and the electrically conductive layer. The electrically conductive layer includes a light shielding layer arranged above the second region. The interlayer insulation film includes a first portion located above the first region and a second portion located above the second region and below the light shielding layer. Before performing the annealing process, an average hydrogen concentration of the second portion is higher than an average hydrogen concentration of the first portion.