A polycrystalline silicon plate has grain boundary lines on a surface thereof, and at least one of the grain boundary lines is a quasi-linear grain boundary line (1). The silicon plate is used to produce a solar cell. The silicon plate is formed using a base substrate having an irregular surface provided with dotted or linear protrusions, which makes it possible to control the grain boundary lines. As such, an inexpensive and high-quality silicon plate can be provided. Further, by employing this silicon plate to produce a solar cell, an inexpensive and high-quality solar cell can be provided as well.