To provide a keyboard device with excellent assembly operability, in a simple structure, capable of securely fixing the light emitting element in a stable state, while preventing the light emitted by the light emitting element from leaking to an adjoining key.

When a plurality of light emitting elements 32 are mounted on a keyboard chassis 6, the plurality of light emitting elements 32 is fixed to each projection section 31 of a first substrate 25, the first substrate 25 is fixed to a fixing section 28 of the substrate fixing member 24, and a fixed section 27 of the substrate fixing member 24 is fixed to the keyboard chassis 6. Thereby, the first substrate 25 is fixed in an erected state, and each light emitting element 32 not in an erected state is provided at the plurality of projection sections 31 of the first substrate 25 inserted into each inner section of the plurality of while keys 7a with a non-contact state. Consequently, the structure is simple, assembly operability is excellent, and the light emitting element 32 is securely fixed in a stable state, while preventing the light emitted by the light emitting element 32 from leaking to an adjoining white key 7a.