To provide a polarization and conversion element with yields a projection type liquid crystal display in which a display quality is scarcely deteriorated and to provide a projection type liquid crystal display in which the polarization and conversion element is used.

A polarization and conversion element 60 which is composed of at least two linear polarization plates 62 and 63 which are so laminated that the respective absorption axes are substantially coincident is provided. The linear polarization plates 62 and 63 are usually laminated on a transparent base plate 61, and in this case, the plurality of the linear polarization plates 62 and 63 may be either laminated on a side face of the transparent base plate 61 or at least each one of the linear polarization plates 62 or 63 is laminated on each of the both sides of the transparent base plate 61. It is advantageous to provide a reflection preventive layer on the outermost faces 64 and 65 which are made contact with air, of the linear polarization plates 62 and 63, further it is advantageous to make the outermost faces 64 and 65 have a contact angle for water not smaller than 80 degrees. Further, the projection type liquid crystal display in which the polarization and conversion element 60 is arranged in the optical path is provided.