A light emitting device includes at least one light-guide member that extends in one direction and that is fixed to a housing in such a manner as to be capable of expanding and contracting in the one direction, at least one light emitting element that is disposed in such a manner as to face an end surface of the light-guide member and that radiates light onto the end surface of the light-guide member, a rigid board that is disposed such that the light emitting element is interposed between the rigid board and the light-guide member and on which the light emitting element is mounted, the rigid board being movable in the one direction with respect to the housing, and a pressing member that presses the light emitting element against the end surface of the light-guide member via the rigid board.