The present invention relates to a keyboard designed so that the depression of any key top (3) causes a correspon­ding switch (2) to be opened or closed through a keay stem (10). An upper board (5) of the keyboard is provided with a plural number of key stem guide holes (8) equally distanced in both the directions of X axis and Y axis. In said upper board (5), four slip stopper guide holes (9) are provided symmetrically with respect to each key stem guide hole (8) at a right angle to each other. Further­more, slip stoppers (13) are provided extending from the bottom of said key top (3), symmetrically with respect to the key stem (10) at 180° to each other. Said key top (3) is available in plural number of sizes, that is, in sizes with the depth of width which is integral-number times the unit size. The key top (3) of the unit size is provided with one key stem (10), whereas the key top of n-times the unit size is provided with n pieces of key stems (10). The keys (1) arranged in the manner described above are designed so that their respective directions can be altered by 90°.