The present invention provides a single crystal wafer, wherein the main
surface has a plane or a plane equivalent to a plane tilting with respect
to a [100] axis of single crystal by angles of .alpha.
(0.degree.<.alpha.<90.degree.) for the [011] direction, .beta.
(0.degree.<.beta.<90.degree.) for the [01-1] direction and .gamma.
(0.degree..ltoreq..gamma.<45.degree.) for the [10-1] or [101]
direction. Thus, a single crystal wafer that can sufficiently bear device
production processes even with a small wafer thickness is provided and
thereby loss of single crystal raw material is reduced. Further, by using
such a wafer, MIS type semiconductor devices and solar cells are provided
at a low cost.