A keyboard having: a base panel, a switch panel including a hole portion, a membrane sheet including a contact portion, a key top adapted to be depressed for switching the contact portion ON, and a housing supporting and guiding the key top to move freely in a vertical direction, including each a tube portion on an upper end side having a guide hole formed for inserting a stem formed integrally with the key top and a flange portion on an lower end side extending laterally around the tube portion in a size larger than the hole portion; wherein the housing is inserted into the hole portion from a back side of the switch panel, the flange portion being attached to the back side of the switch panel.