A keyboard apparatus includes: a plurality of keys; a switching section that detects depression of each of the keys; a top cover that is integrally formed with a partitioning portion separating adjacent keys from each other; a frame member that includes a plurality of key receiving portions which, in a case where the frame member is attached to the top cover, support the keys in a manner that the keys are placed in spaces surrounded by the partitioning portion; a first coupling section that couples the top cover with the frame member; and a second coupling section that couples a first surface portion of the keyboard apparatus including the switching section, with a second surface portion of the keyboard apparatus including the top cover and the frame member with which the top cover is coupled by the first coupling section.