A side-push push-button switch is provided in which the strength of a rear surface side of a housing to which a load is particularly applied by outside force caused by the switching operation of a push-button member is increased to stably mount the housing on a circuit board and ensure reliable and secure switching operation. The push-button switch includes a housing, a push-button member, and a holding frame. The housing accommodates a switch contact. The push-button member is disposed on a front-surface center portion of the housing and configured to press the switch contact. The holding frame of a channel shape covers outer surfaces of the housing. Both ends of the holding frame are secured to front-surface side portions of the housing on both sides of the push-button member.