An electrical apparatus includes a circuit structure, a case provided with a bottom panel and a case peripheral wall, and a cover provided with a cover panel and a cover peripheral wall. At least a part of an inner surface of the cover peripheral wall and an outer surface of the case peripheral wall face one another, thereby forming a housing space and housing the circuit structure within the housing space. A groove is formed in at least one of (i) the entire periphery of the outer surface of the case peripheral wall or (ii) the entire periphery of the inner surface of the cover peripheral wall. This configuration provides a structure that suppresses infiltration of liquid to the inside of the case, and suppresses adhesion of liquid to the circuit structure.