The mechanical keyboard includes a base plate having multiple through openings, a circuit board disposed to a side of the base plate, multiple mechanical keys disposed at the through openings and connected to the circuit board. Each mechanical key includes a keyswitch, a keycap, and at least a transparent piece. The keyswitch is connected to the circuit board. The keycap is mounted on the keyswitch, and the transparent piece is configured to a top side of the keycap. There are multiple display assemblies, each disposed inside a mechanical key between the keycap and the keyswitch. Each display assembly is data-linked to the circuit board through a signal transmission element. The display assemblies may be installed on conventional mechanical keys and may be viewed from different angles. The mechanical keyboard also has longer operation life.